Healing stress fractures and broken bones. Some of the new generation of non-steroidal anti-inflammatory drugs (NSAIDs) - think ibruprofin - apparently interfere with bone healing. In research led by Patrick O'Conner, Vioxx and Celebrex were found in rat tests to greatly delay or even to halt bone healing. Says O'Conner, "Ibuprofin and indomethacin delay bone healing by about one to two weeks in rats, which is equivalent to slowing it down by 25 to 50 percent in humans." Jeremy Saklatvala of the Kennedy Institute of Rheumatology in London say more research is urgently needed, and "In the meantime, people with healing fractures should steer clear of these drugs." (Reported in New Scientist; original research in J. Bone and Mineral Research (vol 17, p 963). (6/23/2002)
Naps. Sara Mednick at Harvard had 30 volunteers perform a difficult visual discrimination task at 9 am, noon, 4 pm, and 7 pm. The control group had a normal day. The first experimental group (one-third of the volunteers) took a half-hour nap at 2:00; the second experimental group (another one-third) took a one-hour nap. Those who didn't nap did about 50% as well in the evening as in the morning. The half-hour group performed about the same throughout the day. But the hour-nappers improved their afternoon performance relative to their second morning performance, and maintained the edge for the evening test. Mednick speculates that the increased short-wave sleep the longer nappers got was a key difference. (Reported in New Scientist; original research published in Nature Neuroscience 10.1038.) (6/19)
Protect your kids' eyes. This isn't strictly running, though the implications apply to runners as well as thier kids. Research by Loren Cordain and Jennie Brand Miller (New Scientist 6 April 2002) suggests that diets rich in refined and easily-digested starches (breads, breakfast cereals, potatoes) can cause permanent short-sightedness in children. The growth of the eye is a delicate process, and if it grows too long the lens can't focus the image on the back of the eye. Short-sightedness (myopia) results. It's well-established that fast-digesting starches - bagels, breads, cereals, processed rice, potatoes, pastas - cause the pancreas to pump out more insulin. It's also known that high insulin levels lead to a fall in insulin binding protein-3. Cordain's and Brand Miller's work suggests that lowered levels of the latter could interfere with the body's ability to coordinate the growth of the eye. Broad epidemiological evidence supports the idea; the researchers are now doing lab experiments. In the mean time, reading about glycemic index (the technical term for how fast starches hit the bloodstream) my save your children's eyes.
How burnout might work. The 6 April 2002 New Scientist carried an article on lifelong fitness which included mention of interesting preliminary results by running physiologist Tim Noakes whose recent research on ultramarathoners suggests a mechanism for burnout. Noakes studied 30 men who'd experienced physical burnout - the somewhat sudden inability to do the workouts they'd always done, to keep up with old training partners, etc. Noakes suspects that "satellite" cells, whose function is to grow replacements for damaged muscle cells, can only undergo a limited number of repair cycles before DNA damages degrades their ability to do so. Noakes belief is that this is an issue for people who race 30K or longer, more than for shorter-distance racers. New Scientist quotes Noakes, "Mu hunch is that whenever you have marked muscle soreness that lasts more than a few days, there is probably damage that's not reversible in the long term."
Imaginary workouts. Just imagining yourself exercising can increase the strength of your muscles. Muscles move when stimulated by nearby motor neurons. These in turn depend on the strength of the electrical signal from the brain. Guang Yue, an exercise physiologist a the Cleveland Clinic Foundation, says, "That suggests that you can increase muscle strength solely by sending a larger signal to motor neurons from the brain." Yue and collegues asked volunteers to imagine flexing one of their biceps as hard as possible in training sessions five times a week. They monitored electrical brain activity in the sessions, and also monitored motor neuron activity to make sure the volunteers weren't actually flexing. Without any measurable growth in the target muscles, the volunteers showed a 13.5% increase in strength, which lasted for at least three months after the training stopped. Reported in New Scientist, 24 November 2001.
Caffeine versus ibuprofin. Inflammation is the body's natural infection-stopping response - the increase in temperature kills invading bacteria and viruses. Sometimes, though, we use anti-inflammatories like aspirin and ibuprofin (generally referred to as NSAIDs - non-steroidal anti-inflammatory drugs). Recent research shows how the body itself shuts down excessive inflammation before it can do harm (since inappropriate inflammation can lead to arthritis and heart disease). The key molecule is adenosine (which is also used to store energy - it's the "A" in ATP). Adenosine binds to a cell-surface receptor to modify the inflammatory response. OK, so here's the kicker. Adenosine buildup in the brain is associated with sleepiness, and the way caffeince works is to block the adenosine receptors. Inference - caffeine may also block adenosine's natural inflammation-managing functions.
Higher-fat diets. Peter Horvath of SUNY Buffalo recruited 25 competitive runners (minimum 40miles/week), spanning ages 18 to 53. Each cycled through three four-week diet regimens. The first included 16% of its calories from fat, the second 30%, and the last 45%. The total number of calories they ate was held constant. At the end of each four-week session, Horvath tested their endurance. Duration of peak output was increased by 7%, overall endurance increased 14%, and exercise-induced muscle fatigue decreased. Blood tests showed the highest fat dieters used their stored fat more efficiently during exercise as well. In addition, Horvath's colleague Jaya Venkatraman determined a better immune response with the higher-fat diets, specifically higher white blood cell counts and reduction in production of inflammatories. In a more recent experiment, Horvath worked with nine female soccer players, varying their diets by 450 calories daily, either increasing fat (from peanuts) or carbohydrates. No change in total calorie intake was made. At the end of each of the three one-week sections of the test (normal, high carb, high fat) each woman ran a 90 minute treadmill test, simulating a soccer game, with the highest intensity reserved for the end. Horvath found the higher-fat diet increased the ability to sustain peak output (about 14 kph, or sub-63 15K) for about a mile longer than the control or the increased carbohydrate diets. Horvath speculates that there may be a selective advantage in this dietary strategy for women, since women use fat about 50% more efficiently than men. For those taking this to heart, recent research by many finds that the monounsaturated fats in nuts, notably almonds, is especially beneficial to overall health.
Echinacea. While other research has indicated that echinacea really does boost immune response, research conducted by Richard Ondrizek found that echinacea, ginko biloba, and St. John's wort diminished sperm's ability to penetrate eggs. (Saw palmetto was also tested and had no such effect.) Untreated sperm penetrate about 63% to 8% of eggs. Eggs incubated in echinacea saw that drop to 13%, and for those exposed to ginko biloba and St. John's wort it dropped to zero. Applying similar treatment to sperm, ginko and St. John's wort damaged the sperm's outer membrane and in the case of St. John's wort, induced mutations in BRCA1, a gene associated with breast cancer. Use with care.
Iron. After reading that the iron in iron cookware was not bioavialable, a surprising (to me, anyway) study released by McGill University found Ethiopian kids whose food was prepared in iron pots had significantly less anemia than those whose food was prepared in aluminum, less than half in fact. Anemia is a common problem for runners, especially women.
But not too much iron. Higher levels of iron in the blood have been associated with higher levels of oxidation of cholestrol and higher rates ot tissue damage from free radicals. These in turn are associated with greater rates of heart disease, cancer risk, and degenerative diseases like arthritis.
Antioxidents. Bruce Trock of Georgetown found head and neck cancer patients who had been taking vitamins A, C, or E had only about one-quarter the mutations in the cancer suppressor gene p53 than those who had not. Maurice Bennink of MSU found orange juice, high in flavonoids, reduce cancer incidence in lab rats. Other researchers have found similar results with lemonade, which contains liminoids. With more lab rats, Samuel Campbell of U. Alabama found that vitamin C reduced blood concentrations of the stress hormone corticosterone, which in people has been linked to heart disease and upper respiratory infection. C also increased the rat's production of IgG, an antibody used to measure immune system function. In research with other rats, Laura Kresty of Ohio State found that eating rat chow laced with freeze-dried black raspberries resulted in up to 48% fewer tumors in response to a cancer-inducing chemical when compared to rats fed a normal diet. Kresty attributes this to the raspberries' ellagic acid, an antioxidant. Other research has shown strongly positive effects from blueberries.
Now the bad news. While antioxidants appear to reduce the risk of getting cancer, if you already have it, they may aid its growth. Rudolph Salganik and colleagues at U. North Carolina at Chapel Hill fed genetically modified mice one of two diets. The mice in the study have been bred to study cancer, and the genetic modification invariably results in brain cancer. Salganik and his team fed two groups of mice normal and reduced-antioxidant diets; in the second diet, 90% of the antioxidants (vitamins A and C) had been removed. When the cancerous brains were biopsied, tumors were half the size in the low-antioxidant group. In addition, seven times more cells in the low-antioxidant group were undergoing apoptosis, a programed cell death driven by free radicals and ordinarily used by the body to rid itself of diseased or damaged cells. Salgalnik noted that the difference in apoptosis was limited to the cancerous cells, which suggests use of antioxidants does not interfere with the process in normal cells.
Free radicals. Knowing that intense exercise releases a large volume of free radicals, many athletes take anti-oxidents like vitamins C and E. To test whether anti-oxidents improve either performance or recovery and subsequent performance, racing greyhounds were given vitamin C. Geyhounds are exceptionally consistent in their performances, so they make a good test group. To the researchers' surprise, anti-oxidents resulted in consistent small decreases in performance. No-one has any idea why. (7/30)
Watermelon: Food for Men. Not as weird as it sounds. Turns out watermelon is exceptionally high in lycopene, which is known to be very good for the prostate. (Also, watermelon is the greatest thing in the world after a long run.)
Female competitiveness. In a result that may or may not mean anything, Rosanne Roy of McGill set up a game that in two variants either had all participants win, or one only. She set up forty groups of either four boys or four girls, aged 5 -6 or 9 -10, and found that the boys would compete regardless of whether there would be a single winner or not. Girls generally chose to compete only in the variant of the game when it was possible to win. The problem with this kind of research is that you can interpret it any way you want - boys are sensitive to thier inner selves (they competed purely to engage in the process) while girls are much more superficial (they only compete for external rewards). Obviously, this was not Professor Roy's preferred interpretation (which was, roughly speaking, boys are competitive to the point of stupidity). (Research reported at the International Society for Human Ethology conference, August 2002.) (For a serious look at female competitiveness, see Sarah Blaffer Hrdy, Mother Nature, Pantheon, 1999.) (9/11)
Demographics. This isn't strictly running-related, but... Women like men who aren't patriarchal. For many men, there's a sense of, "yeah, they say that, but do they mean it?" Recent demographic trends emerging in Europe show that when it comes to voting in the most profound way possible, women in patriarchal southern Europe (Italy, Spain, Greece) are having fewer and fewer children - in fact, far below replacement rate. While family sizes are also shrinking in more-enlightened Scandinavia, they are doing so to a significantly lower degree. Bottom line for single guys: diaper-changing skills make you a babe magnet. (From New Scientist, Aug 2002) (9/8)
Stretching probably useless. Rob Herbert of
the University of Sydney conducted a meta-analysis of the scientific studies
of stretching published in the past 50 years. As quoted in Nature, Herbert found
five published studies with samples large enough and controls good enough to
be considered reliable. All measured the effects of stretching on muscle soreness;
two also looked at injury risk. None of the studies showed any significant benefit.
"We can say with a high degree of confidence that stretching
does not prevent muscle soreness," says Herbert. "We can't rule out
that it reduces injury risk, but the weight of evidence is against it."
[Ref.: Herbert, R. D. & Gabriel, M. Effects of stretching before and after exercising
on muscle soreness and risk of injury: systematic review. British Medical Journal,
325, 468 - 470, (2002).]
However... Gary Milliken represents a lot of non-22-year-old runners
when he writes, "I read with great interest the report on stretching. I
can't argue with the conclusion, but it's worth emphasizing two important points.
"First, the study was done with Army recruits which I
assume means guys approximately 17 to 22 years old or so. I know I could do
many things at that age that would put me in traction today, so the results
may not apply to someone my age (52).
"Second, the study made no claims about the benefit of
stretching after exercise for the prevention of injuries. But from my experience
stretching after exercise is the most beneficial time to stretch, especially
if for preventing injuries.
"By stretching after exercise I know I can get a deeper
more comfortable stretch that seems to help prepare me for the next day's workout.
Since I'm only a sample of one, this isn't science, but I can tell you my experience.
"After what I think was a calf tear in June I got serious
about a stretching routine. Since then, every other day - on my easy days, I
run 4 easy miles at a pace about 1 1/2 minutes slower than my 10K race pace,
and then I do several stretches emphasizing the backs of my legs - Achilles,
calf and hamstrings. I'm more flexible now, and even though I have increased
my mileage, I have not had an injury since I've started stretching regularly.
I am reasonably sure the stretching after running has helped me prepare for
the next day. It would be interesting to hear what other runners have learned
about stretching."
Science: Raisins and oxidation. Terry Howell passed
on an article
on the effects of raisins as an in-competition food. In research spnosored by
the California Raisin Council, triathletes completed two pro-distance triathlons
two weeks apart. In the first, half got raisins and half got the same number
of calories in a glucose drink. In the second, the groups were reversed. The
researcher found the raisins resulted in significantly less oxidative damage
to DNA taken from post-event urine samples. An interesting result.
A little caution may be reasonable, though. First, the
research was presented at a conference, not in a peer-reviewed journal. Second,
industry-sponsored research (in this case, that attributes benefits not to raisins
generally, but specifically to California raisins) has not proved to be the
most reliable in the past. (In general, researchers whose work is good enough
to earn funding from the National Science Foundation don't apply to industry
promotional groups for grants.) Third, no athlete would actually take a pure
glucose drink when exercising - you can't buy one; sugar-water is actually a
mixture of sucrose and fructose - but how raisins stack up against modern sports
drinks wasn't reported. Fourth, the sensitivity and specificity of the DNA testing
wasn't reported - there is more than one way to test DNA. Finally, the effects
of antioxidents and of oxidative damage during exercise are not even close to
well-understood. On the plus side, though, raisins are pretty good. (10/8)
Quick replenishment. More studies on rats, but this mechanism is known to transfer well to humans. Richard Anderson of the USDA looked at glucose uptake by fat cells, and found that cold tea boosts uptake by a factor of fifteen. (That's a lot.) Herbal teas had no effect; milk and soy limit it. The report doesn't discuss green teas. What this means - after a hard workout, restoring muscle glycogen is the first step to recovery. Apparently spiking your carb + protein drink with tea tremendously accelerates absorbtion. To be published in J. Agricultural and Food Chemistry (reported in New Scientist, 26-Oct-2002). (11/9)
Cold hands. OK, all the female readers with me now? (And of course all you guys who have the privledge of sharing those icy hands and feet when you crawl into bed.) Seriously, managing heat is one of your body's biggest tasks when exercising. In order to shed heat, blood is diverted from the deep organs to near the surface of your skin, especially your hands and feet. (Your head, as well, though that's mainly because although your brain is about one-fiftieth of your weight, it consumes about 30% of the oxygen you breathe - so there's always tremendous flow.) Diverting oxygen-carrying blood away from the muscles to the skin has the obvious effect of making the muscles less efficient. Chris Heller and Dennis Grahn at Stanford made a "glove" - essentially a small vacuum chamber with a heat-sapping water-cooled steel plate for the hand - that sucks heat from the body with high efficiency. This allows more blood to flow to the muscles and internal organs and less to the skin. In tests with eight professional cyclists, using the glove resulted in performances 6% faster in a 30K time trial than without. That is an incredible difference. Downside - the cylicsts were on a treadmill, and we runners aren't likely any time soon to be carrying water-cooled steel plates on our hands. What it does suggest, though, is that the elite marathoners you see running through 40-degree weather in Chicago in just shorts and singlet know exactly what they're doing. (Reported in New Scientist, 26-Oct-2002). (11/9)
Coffee unlinked from high blood pressure. Standard medical advice to high blood pressure sufferers has been to cut out caffeine. Zurich researcher Roberto Conti reports that "ingredients other than caffeine are responsible for the stimulating effects of coffee on the cardiovascular system." Counterintuitive - No-Doz seems to work, and the caffeine in colas and tea has an effect indistinguishable from coffee when normalized for dosage - so it will be interesting to see the research replicated. Nevertheless, it strongly suggests that the link between coffee consumption and hypertension is not based on caffeine - decaf would have the same effect as regular. In addition, the strength of that link, when compared to something like salt, is very small (according to Simon Thom of St. Mary's in London). Conti's team's research will be published in Circulation. (11/19) (Thanks to Dennis Mihora for forwarding this.)
Evil but good drug even better. Erythropoietin - EPO - is widely known to runners as the anemia drug abused by cheating endurance athletes to boost red blood cell counts (and therebyboost their blood's oxygen-carrying capacity.) Emerging findings from a variety of researchers are suggesting that EPO may also be a nerve-protecting drug that minimizes long-term damage from strokes and spinal cord injuries. In a number of experiments, administration of EPO immediately or shortly following traumatic injury had dramatic effects, including (with rats) making the difference between permanent paralysis and near-complete recovery of function. (Summary article in Science News (162:19). (11/18)
Hot rocks mating. Female lizards in Arizona prefer
the big, strong guys to mate with. However, when researchers moved the best
basking rocks from the big guys' to the littler guys' territories, the females
followed the good rocks, dumping the big guys for their smaller competitors.
Better housing. However, when the researchers followed up with DNA testing of
offspring, it turned out the females had snuck back to the big guys to get pregnant
- with males. They dallied with the smaller guys to get pregnant with females,
though.
In a totally unrelated note, high-status human males
have more male offspring than low-status males - or probably more accurately
stated, females who mate with high-status males have more male offspring, since
there's some evidence that women may determine the gender of their children.
One wonders if as there are increasing numbers of autonomously high-status females,
whether the male/female ratios amongst high-status pairs will change...
However, it's obvious the idea that a human male's offer
of a particular kind of rock to a human female might influence her choice of
mating behavior is absurd. (11/18)
Loud noise = reduced performance. Italian researcher Giada Frenzilli of U. Pisa has found that prolonged exposure to loud noise can cause a significant rise in the level of the hormone noepinephrine, which then causes heart cells to absorb too much calcium. That in turn weakens mitochondria membranes, which has the twin effects of releasing damaging free radicals and reducing effective mitochondria density. (Mitochondria are what allow us to use oxygen, and a big part of distance training is increasing mitochondria density.) The damage persisted at least 24 hours. Frenzilli's team also determined that (non-mitochondrial) DNA was damaged (a result of the exposure to the free radicals). It isn't clear whether the cause is uniquely the noise or is a generalized stress reaction to the intensity of the stimulus (100 decibels, about what you'd find in a dance club or loud industrial workplace). Makes one long for the silence of Death Valley. Reported in Science News (vol. 163, 1 Feb 2003). (2/7/2003)
Two notes on heart
disease. Simple one first: the British Medical Journal (vol
325, p 1202) reports "lowering homocystine concentrations by 3 micromoles
per litre from current levels (achievable by increasing folic acid intake)
could would reduce the risk ischaemic heart disease by 16 percent." (Italics
added.) Easy to do, and folic acid has recently been tagged as beneficial for
all sorts of things.
The second is more profound, a rethinking of how heart
disease works. Since the 80's the dominant theory has been the "clogged
pipes" (plumbing) theory. One's arteries fill with plaque until they
are so jammed that blood can no longer traverse - and you have heart pain
(angina). Worse, a plaque breaks loose, causes a clot that blocks an artery
completely, causing a heart attack. The implication - reduce cholesterol,
which is the raw material of plaques. The problem with the theory is that
about half the men who have heart attacks have normal levels of cholesterol.
The emerging theory, bolstered by a recent large study, is that the core
of heart disease is inflammation. In this model, atherosclerosis (plaque
buildup) is really the result of runaway inflammation. There is a lot of
detail to the theory - that statins, for example, prescribed to reduce heart
disease risk, actually work by reducing inflammation; that estrogen may
be a functional anti-inflammatory and this is why pre-menopausal women have
far fewer heart attacks than men; that various bacteria and viruses really
do increase the risk of heart attack, again by triggering inflammation -
there's more, but that's enough for here. Bottom line, take your aspirin
a day. (But - please note the FDA-recommended dosage is 50 - 350
milligrams/day, and the typical adult aspirin is 350, right at the top of
the range. Many prefer one baby aspirin a day for a reduced dosage. Or just
break it in half.) Reported in New Scientist 11 Jan 2003.) (1/31/2003)
Get more sleep. The U. Penn med school ran a study with 48 young adults and found that two weeks of six hours of sleep a night impaired mental abilities as much as not sleeping at all for two nights. Even more startling, the six-hour-a-night subjects failed to recognize how badly they did on the evaluation test, and they didn't report feeling sleepy - they thought they were fine, but they weren't. Many of us go through life with less sleep than we probably need; if you'll pardon the bad pun, this study is a wake-up call. (Original research in Sleep, vol 26, p. 117.) (4/1)
Hope to have kids? Non-human studies have to be interpreted carefully, but fruit fly experiments with the common energy bar additive chromium picolinate found serious DNA damage in offspring of flies given equivalent (low) doses, with elevated levels of sterility and the damage effect extending over four generations. Your body doesn't need chromium picolinate supplimentation; if you think you might want children (or more children) you may want to avoid it. (Original research published in Proc. National Academy of Sciences, DOI: 10:1073/pnas.0636646100.) (4/1)
Sole feelings. Research in Australia considered the ability to sense ankle invesion, the turning of the ankle inward toward the body. The Australian women's national soccer team were the subjects, and thier barefoot scores were higher than their shoe-wearing scores. Padding that reduces sensory feedback from the soles appears to lead to a greater liklihood of injury; in one study, basketball players wearing air-cushioned shoes were four times as likely to get ankle injuries as players wearing regular shoes. Interestingly, by placing small nodules in the insole (3 mm, four per cm2), the soccer player's sensitivity was returned to barefoot level. Take-home message: unless you only run on very hard surfaces, minimal cushioning and maximum feedback thorugh your shoes appears likely to reduce injuries. (Research published in British J. Sports Medicine, Vol. 37, p. 170.) (Also see Tips page, on buying shoes.) (4/17)
It doesn't matter too much what you drink. For hydration, anyway. Apparently the water in Omaha is as bad or worse than Santa Barbara's. Following up an inquiry from elite athletes whether drinking soda or juice was as good as plain water for hydration, researchers at U. Nebraska Medical Center strictly controlled and monitored fluid intake for 27 male athletes for three days. One group took half its fluid from plain water; the other group had only juice, coffee, and cola. At the end of the three-day trial there was no difference in hydration. Flat Coke mixed with skim milk, here we come! (Research published in J. American College of Nutrition, vol. 22, p. 165.) (No word yet on the local Hasher's proposal to repeat the study using only beer. Most likely, they already have...) (4/17)
Medicine - women. A study released today suggests a mild increase in the likelihood of dementia in women who take HRT - "hormone replacement therapy" - specifically, those who take the commonly prescribed combination of estrogen and progestin. And earlier study found increased risk for breast cancer, heart attack, stroke, and blood clots in women taking the hormones. UCLA's Dr Jeffery Cummings was quoted in the LA Times as saying, "Unequivocally, we'll now recommend that estrogen plus progestin does not offer a benefit and may be a risk factor." (Source LA Times, 5/28/03, original research published in JAMA.) (5/28)
Medicine - men. Men are often encouraged to get biopsies when their PSA (prostate-specific antigen) levels are found to be elevated in blood tests. While PSA tests have been know to be poor indicators for a number of years, a study released today (also in JAMA, the Journal of the American Medical Association) indicates that it's generally a mistake to get a biopsy based on a singel elevated PSA test. The study authors recommend waiting at least six weeks and having a second PSA test. Even then, if both tests show elevated levels, the chances of actually having prostate cancer are only about one in four. (Source LA Times, 5/28/03, original research published in JAMA.) (5/28/03)
Men, women, and babies. Not strictly
running here, but interesting. Women tend to be more peripherally conscious
than men visually, while men tend to focus attention in a narrower, frontal
field. Probably as a consequence, women are more conscious of their lateral
personal space and report discomfort when intruded upon from the side, while
men are more conscious (and defensive) of their frontal personal space.
Now babies. While the findings are far from definitive,
using soy-based formula appears to be a bad idea. Soy is high in phytoestrogens
(plant compounds that mimic estrogen, a key hormone). In one study, girls fed
soy-based formula as babies reported longer and more uncomfortable periods.
Another study followed 8000 boys, finding that those born to vegetarian mothers
(most likely to consume higher levels of phytoestrogens) had five times the
number of genetic abnormalities. (Of course this evidence is equivocal unless
the study controlled for whether vegetarian mothers were more likely to nurse.)
Animal studies of phytoestrogens consistently suggests the overly-high levels
result in developmental damage. Bottom line - if you've got a baby and don't
have a compelling need to use a soy-based formula, then don't. (Source: New
Scientist, 17 May 2003.) (5/27)
Downward slope. As though we needed more reminders of the effects of geezerification on men, a new study of pregnancy finds that men over 45 are five times more likely to take more than a year to impregnate their partners than men 20 and under. (If you're a male over 45, did you need to know this?) (Fertility and Sterility, vol. 49, p.1520). (7/17)
Sex lives. A common assumption is
that young men have more active sex lives than similar-aged women. Research
conducted by Terri Fisher at Ohio State and published in J. Sex Research (reported in the LA Times)
suggests that what people say and what they do may be different. Fisher and
her colleagues placed unmarried college-age women in three groups. The first
believed the researchers would see their personal responses to the questions,
the second believed the researchers would not, and the third were attached to
a (sham) lie detector. The "lie detector" group reported twice as
many sexual partners as women who believed the researchers would see their responses,
with the women who thought the researchers would not see their responses in
between. Men divided into corresponding groups showed little or no change based
on group. Fisher's (reasonable) interpretation is that because sexually adventurous
women are still socially stigmatized, they are less likely to admit to that
behavior.
Gals, you may find this amusing (but true). Guys, don't
worry, your wife/girlfriend told you the absolute truth about her
life before she met you. (7/23)
Rhythms and cycles. In 1953 Eugene Aserinsky and Nathaniel Kleitman discovered the fundamental 90-minute basic sleep rhythm, the alternation of rapid-eye-movement (REM) with deep sleep. Subsequent research has found that this cycle is a property of virtually all life, and pervades our waking life as well as our sleep. Ultradian clocks (clocks with a cycle of less than a day) running at the same 90-minute cycle have been found in amoebas, yeasts, protists, and us - they govern and coordinate cells' creative and destructive processes. Yet another example (as though one were needed) where our self-awareness is self-limiting - we don't notice the variation in alertness and activity during the day because the mechanism by which we'd notice is itself subject to just the same variation. It certainly grounds the hard/easy concept at a deep level. (7/29)
Women who want babies (or don't). Obviously men are included too. In the first study of its kind, daily ultrasound imaging was used to monitor ovulation for six weeks. The surprising result is that about ten percent of the women in the study ovulated twice in a single cycle, on two separate days. Whichever way you're planning, something new to take into account.(Research by R. Pierson at U. Saskatchewan, reported in New Scientist, 19 July 2003, p.16.) (8/1)
Aspirin, ibuprofin, and pregnancy. Researchers at Kaiser found a stong link between miscarriage and women's use of aspirin and ibuprofin (Advil) at the time of conception and early in pregnancy. No such link was found with acetaminophen (Tylenol). The study was of modest size, but since runners tend strongly to favor ibuprofin and aspirin, worthy of consideration if you're planning a child.(Original research reported in the Aug. 16 British Medical Journal.) (8/30)
Creatine and memory. For sprinters
and lifters, creatine has long been one of the most popular supplements, a $200
million market in the US alone. In surprising research, a team led by Caroline
Rae of U. Sydney found that creatine supplements resulted in improved performance
on memory and analytical tasks.
Forty-five vegetarian university students spent twelve
weeks in the trial. In a double-blind test, for one of the six week blocks they
received a creatine supplement, for the other a placebo. Vegetarians were chosen
since beef-eaters (or if you prefer, cow-eaters) get creatine as part of their
diet, so a more pronounced effect was expected.
Creatine is an amino acid and the researchers
hypthesize that the improved short-term energy metabolism it supports would
aid concentration - which is exactly what they found. Markus Wyss of Roche in
Basil points out that the long-term safety of creatine suppements hasn't been
determined, and that it may be problematic in people with diabetes or kdney
dysfunction.Nevertheless an interesting an unexpected result. (Reported in Science
News vol. 164, original research to be published in P. Royal Society
of London B.) (8/30)
Dirty supplements. After a number of drug
findings of nandralone among track athletes who claimed they'd only taken supplements,
the IOC actually did some research (instead of the morally superior chest-beating
that's more typical). In a report released April this year, IOC-funded researchers
summarized chemical analysis of 634 different supplements commonly used by athletes,
bought in 13 countries. They found an incredible 14.3% were "dirty"
- had substances not listed on the labels that would cause a failed drug test.(Results
reported in the LA Times, 27 August.)
This means that athletes' reputations have been smeared
and careers ended by some manufacturers' shoddy, unprofessional work. It also
means SBAA members who take supplements should be careful in selection. (A second
reason for care is that supplements vary widely in potency - independent tests
have found that the bottle promising 500 mg of such-and-such can mean anything
between 50 and 500.) Unfortunately, pretty much the only thing you can do is
look for a "GMP" (good manufacturing processes) label on the bottle,
or a note that the supplement is pharmaceutical-grade. Since supplements aren't
regulated, neither of these is a gaurantee, but either or both are currently
the best options available. (8/30)
How drug tests work. Track fans may
be aware of the news of a failed drug test by Bernard Lagat, generally regarded
as a great guy. Lagat denies taking EPO, while sportswriters are ready to condemn
immediately. It might be useful to look at how the numbers work.
It's hard to find accurate measures of the effectiveness of
the EPO test. The test creators claim extraordinary specificity (only finds
EPO) and sensitivity (no "false positives" - a finding that EPO is
present when in fact it is not) in 3500 cases. However, other authors are more
conservative (and realistic) in accuracy claims. To get a feel for the numbers,
let's say the test is 99.5% accurate.And for discussion, let's say one in two
thousand athletes actually use EPO. (No-one knows the real number of users.)
Suppose 10,000 athletes get tested. If an athlete gets
a positive test for EPO (which is 99.5% accurate, remember), what is the real
likelihood he or she is taking EPO?
All 5 athletes taking EPO are caught.
That 0.5% of 10,000 results in 50 athletes who aren't
taking EPI being "caught."
So a total of 55 athletes have a positive test.
Being caught means you have a 1-in 11 chance of being a cheater. Said another
way, you have a 91% chance of being falsely accused.
As I said above, I don't know the real numbers.
But a positive test for a drug doesn't mean someone has taken the drug. If the
numbers above are right, in fact, it would mean about a 90% chance of not
taking the drug.
All this assumes no human error - no mislabeled or mistakenly
switched samples, no contamination in the lab, everything goes exactly perfectly.
Please don't judge until all the evidence is in. (9/6)
Magnets don't work. At least for plantar fasciitis. Mayo Clinic researchers gave 101 plantar faciitis sufferers either a magnetized insole or one with an inert same-weight metal. After eight weeks the two groups showed no difference in the rate of healing. (Original results in JAMA 17 Sept., reported in Science News [vol.168, p. 254].) (10/27)
Microwave cooking destroys nutrients.
Work done by Cristina Garcia-Viguera and team measured flavinoids (antioxidents)
in broccoli after steaming, pressure-cooking, boiling, and microwaving. While
steaming left levels nearly the same as those found in raw broccoli, pressure
cooking cut them by more than half, boiling by over 80%, and microwaving nearly
eliminated them. (Our bodies do not absorb the nutrients from raw foods as efficiently
as from cooked.) Garcia-Viguera believes that the internal cell heat generated
by microwaves is the cause.
Additionally, the blanching typically done to vegetables before
commercial freezing also decreases nutrient content (research by Riitta Puupponen-Pimia).
Both studies appeared in J. Science of Food and Agriculture, vol.
83 (reported in New Scientist [25 Oct 2003]). (10/29)
Add note. The experiment protocol compared 3 1/2 minutes of steaming
to 5 minutes of microwaving, for not a lot of broccoli, so it's a legitimate
criticism of the study to wonder if the real finding wasn't about microwaving
per se, but rather about overcooking.
But don't throw out the microwave yet. Earlier we reported results suggesting microwave cooking destroyed nutrients. However, the results may not be as clear as initially reported. The experiment protocol compared 3 1/2 minutes of steaming to 5 minutes of microwaving, for not a lot of broccoli. It's a legitimate criticism of the study to wonder if the real finding wasn't about microwaving per se, but rather about overcooking. (11/27)
Supplement summary. The National Institutes of Health supports the scientific study of supplements. Their annual summary of results is available at the Office of Dietary Supplements. (10/29)
Chocolate fans might not like this. Jeannie Brand-Miller, a leading (maybe the leading) glycemic index researcher, found that cocoa powder caused a 28% spike in insulin levels as compared with the same foods minus the cocoa powder in tests with 11 lean young adults. Blood glucose levels were the same for both the foods, so it wasn't merely a response to differing concentrations of blood sugars. Insulin is produced by the pancreas and is used by the cells to extract glucose from the blood. The spike means glucose is absorbed faster, unfortunately followed by a corresponding drop as the rapid withdrawal depletes available resources. (Which probably makes you want more chocolate...) If you're trying to follow a low glycemic index diet (which you probably should be), sadly, chocolate is no longer your friend. (Original research in J. Nutrition, reported in Science News, vol. 164.) (11/3)
Live high, train low. The Johnson brothers of www.letsrun.com have advocated this for a while. An Australian group took 22 elite distance runners and using a low-oxygen enclosure like that used by the Nike-sponsored and Salazar-coached Oregon Project runners, grouped them into a test, and intermediate, and a control group. Their conclusion: "There was no evidence of an increase in [lactic acid] after the LHTL [live-high, train-low] intervention suggesting that the lower aerobic cost of running was not attributable to an increased anaerobic energy contribution. Furthermore, the improved RE [running economy] could not be explained by a decrease in VE [ventilation], by preferential use of carbohydrate as a metabolic substrate, nor was it related to any change in Hbmass. We conclude that 20 d LHTL at simulated altitude improved the RE of elite distance runners." In regular English, it worked, impressively, in less than three weeks. (Saunders et al., abstract available from PubMed.) (11/14)
Love, suspicion, and more chocolate.
Notes from the Society for Neuroscience annual meeting:
Love. Brain
imaging has to be interpreted with some degree of care; the relationship between
brain and mind is only beginning to emerge. With that caution, some interesting
results. The "madly in love" infatuation phase doesn't actually
seem to involve the emotional brain. Instead, it heavily involves the motivation
and reward areas of the brain (dopamine heaven). It's only later, as a relationship
matures, that the regions of the brain associated with emotion become more
involved. (Personal note: This supports a belief I've long held, I'm sure
in common with many readers, that the strongest long-term relationships start
off as gradually-deepening friendships.) Said another way, the wild infatuation
phase has much more in common with powerful drives like hunger and thirst
than with the complexities and satisfactions of love in the long term. An
aside to gratify a certain segment of the SBAA membership, the same
regions activated when madly in love - the right caudate nucleus and the right
ventral tegmentum - are also activated by chocolate.
Suspicion.
Oxytocin is the "love and trust" hormone, strongly associated with
positive interpersonal feelings. It's released in floods after childbirth, for
example. With a pretty obvious evolutionary utility, when women ovulate hormone
levels of progesterone rise, and it turns out progesterone is an oxytocin inhibitor.
For ovulating women, this means highest fertility = lowest oxytocin = greatest
levels of suspicion about that guy claiming to be your One True Love.
Atkins diet
ages the brain. Two sets of researchers have found that diets rich in fruits
and vegetables (with their naturally occuring antioxidents) protect the brain
from aging. Hard-core Atkins followers, who skip vegetables and especially fruit
for meat, may be more likely to experience cognitive problems as they age.
Alcohol.
Karolinska Institute researchers found (with rats) that alcohol does kill brain
cells, but at moderate dosages new cells are born in the same regions. Only
high-dosage alcohol causes a permanent loss.
But before
you get too excited by all the new neurons you're growing by knocking down a
brewski, know that for several days after we die the brain continues to generate
new neurons. Intriguingly for runners, this is apparently because the brain
releases growth-stimulating chemicals in response to lack of oxygen.
(All results reported in New Scientist, 22 November.) (11/26)
EPO test. Bernard Lagat's medical expert reviewed the testing of his B sample. You can download his entire report, but one conclusion is, "the antibody used does not provide an unequivocal identification of rhEpo and specifically does not discriminate between natural and recombinant erythropoietin!" This means that since every normal person's kidneys produce EPO all the time, there are always trace amounts of EPO in everyone's urine. That's why the scientific author included the exclamation mark (not a commonplace in scientific writing). The report raises such serious doubts about the current protocol that Lagat's call for a suspension of EPO testing until a better test can be developed is valid and appropriate. (11/27)
The future of drug testing. Training
works though regulating gene expression, which in turn regulates protein production
(and every other adaptation to training). Some on the leading edge of drug testing
believe that directly detecting this would both bypass the current difficult
process of mass spectrometry, and cast a broader net without sacrificing accuracy:
if the house is burning, we don't care what was used to ignite it. If drugs
artificially stimulate the same genes training does, though, how could the drug
user be separated form the exceptionally gifted? Molecular biologist Annie Toth
comments:
"Performance enhancing drugs certainly do alter gene
expression, and they probably do so in a similar way that the body's natural
hormones do. It may, therefore, be rather difficult to distinguish between drug
abusers and the exceptionally gifted. However, performance enhancing drugs have
slightly different chemical structures than the natural molecules they try to
mimic (for example EPO vs. natural erythropoeitin made in the kidneys), and
they may therefore regulate genes slightly differently. A drug abuser could
be distinguished from an athlete by expression levels of certain 'marker' genes."
(Annie, by the way, is running again regularly after seven
frustrating months of Achilles tendonitis.) (11/9)
'Athlete's heart' trouble? Danny Green, a
researcher at U. Western Australia, has published evidence that when highly
fit athletes stop training, even temporarily, their heart function resembles
that of people with heart disease or high blood pressure. "If you look
at the hearts of people with cardiovascular disease or high blood pressure,
you see that their hearts are quite similar to those of these athletes. During
the resting phase of the heart, athletes appear to have abnormal function like
you see in people with disease, so it raises the question about whether there
are long-term detrimental side effects for athletes. This is the first time
in the world that this very interesting preliminary finding has emerged."
Pre-fitness-boom folklore held that youthful athletes
had a much higher risk of heart trouble as they aged. While Green's finding
flies in the face of overwhelming evidence that exercise any time is good for
you, it addresses something few studies do, i.e., the hard-core, highly fit
athlete. One wonders about the interpretation of the evidence. A heart murmur,
for example, can arise from two sources, a faulty valve (common, and a sign
of potential heart disease), or from a a big, powerful pump pushing blood through
a small hole (hard-core athlete). More study is needed, but in the meantime,
one more reason to manage your racing seasons and running career so you can
still compete into your 90's. (12/11/03)
Fitness by genetic therapy. "When
you exercise, your muscles change fiber type specificity, switching from type
II fibers to type I fibers," says Dr. Rhonda Bassel-Duby, associate professor
of internal medicine at UT Southwestern. "When we expressed this protein
[PGC-1Q] in the mouse model, we found that the muscle switched from a type II
muscle to a type I muscle. The presence of this protein alone switched the muscle
type." Type II muscle is easily fatigued; exercise converts Type II to
fatigue-resistant Type I. Already demonstrated in mice, gene therapy with PGC-1Q
has the potential in humans to produce genuine fitness without exercise. (Original
research in Nature, 15 August 2002, reported in ScienceDaily.)
Comment: Athletic drug users have taken legitimate
medical advances - synthetic human growth hormone, synthetic EPO - and subverted
them for illigitimate uses. Producing fitness in immobilized heart attack or
accident victims using gene threrapy is a legitimate and worthy medical goal.
There can never be a doubt this good hugely outweighs the potential for misuse,
but for the endurance athletic community this kind of gene therapy (and its
inevitable wilder variants) means in twenty years the current drug situation
in sport will seem almost painfully simple. (12/30)
Iron a two-edged sword. Simple version:
Just-published results implicate iron as attacking the brain in middle age and
later.
More: Myelin is crucial for effective brain function. In
middle age, myelin breaks down, resulting in loss of brain function. Levels
of cholestrol and iron continually build during life, hitting a threshold somewhere
in midlife when they stimulate protein production that degrades the brain's
myelin, which in turn degrades the internal signaling through which the brain
works. Our mental capacities decline.
Runners, especially vegetarians, take iron to prevent anemia,
but this result suggests that moderation is appropriate. An interesting circumstantial
confirmation comes from the lower incidence of Alzheimers in women, who characteristically
have lower iron levels than men. (Original research published in Neurobiology
of Aging [January 2004], reported in ScienceDaily.) (12/31/03)
Glucosamine + ibuprofin. From ScienceDaily:
"The nutritional supplement glucosamine boosts the pain relieving power
of ibuprofen, according to a new study by Temple University researchers in the
Journal of Pharmacology and Experimental Therapeutics (JPET). Ronald Tallarida,
Ph.D., and Alan Cowan, Ph.D., of Temple's School of Medicine, and Robert Raffa,
Ph.D., of Temple's School of Pharmacy, conducted the study "Antinociceptive
Synergy, Additivity, and Subadditivity with Combinations of Oral Glucosamine
Plus Nonopioid Analgesics in Mice," which was published in the November
2003 issue of JPET."
Glucosamine is taken by older athletes (including the
author) for its clinically-demonstrated benefits to soft-tissue health and bone
repair. Ibuprofin is a non-steroidal anti-inflammatory drug (NSAID), sold under
its generic name or as Advil. (1/8/04)
Farmed salmon. In the coming issue of Science, a study finding high levels of PCBs in farmed salmon suggests eating it no more frequently than once a month. (Some people would translate that to: not at all.) Some people prefer salmon for the high levels of omega-3 fatty acids; farmed salmon is not the way to go, apparently. This also raises the issue of sources of omega-3's in dietary suppliments, something not addressed in the research. (1/8)
GMO athletes. But bad for running,
and athletics in general. Some readers may be aware of genetic engineering that's
resulted in 'mighty mice,' mice who look like hard-core steroid stackers but
show none of the deleterious effects and maintain their powerful (for mice)
physiques even without exercise. The prospect of this kind of gene therapy for
those with, for example, muscular dystrophy or prolonged immobilization is near-miraculous.
However, since the liver filters the blood, catching the 'denatured' viruses
that carry modified genes to their targets, such therapy has only been possible
with extreme intervention. Not practical for working medicine. A significant
barrier has just been passed, as a team in Glasgow has developed a "stealth"viral
carrier that the liver ignores. Lead author Andrew H. Baker, Ph.D., says, "It
may be possible to design and construct genetically engineered 'designer' gene
therapy for selectively delivering genes to any part of the body." Baker's
team specifically targeted cells that line the veins and arteries, critical
to the circulation of the bloood. But for a wide range of illnesses, this is
an extraordinary development that has the potential to revolutionize medical
treatment.
For those in need. This also means it's just a matter
of time until we see genetically modified athletes: Distance runners with dolphins'
oxygen carrying capacity and rabbits' explosive power.
Reported in ScienceDaily,
here.
(1/20)
Coffee reduces likelihood of Parkinson's. Parkinson's is a degenerative disease of the nervous system, marked by palsy and a distinctive shuffling walk. A large-scale study at U. Hawai'i found that coffee drinkers were less likely to get Parkinson's: "Our findings indicate that higher coffee and caffeine intake is associated with a significantly lower incidence of PD. The data suggest that the mechanism is related to caffeine intake and not to other nutrients contained in coffee." Nehlig et al., original research published in Science. (1/11)
Stoned. Researchers at Georgia Institute of Technology and UC Irvine have found high levels of anandamide in young men who ran or cycled at a moderate rate for about an hour. ("Wow," you say to yourself, "anandamide. I've always suspected that.") Anandamide is a cannabinoid, the class of molecule that gives marijuana its psychoactive effect. (1/24)
Estrogen and the neurobiology of stress. Becca Shansky, a Yale grad student, published a report in the March issue of Molecular Psychiatry detailing her discovery that high levels of estrogen increase the brain's reaction to stress. Women have twice the levels of stress-related mental illnesses as men, but this is only true post-menarche and pre-menopause. While the traditional expanation (among women) has been that this is the inevitable result of living with men, the protocol of Shansky's research (supported by her advisor, Amy Amsten, MD) presents a strong finding that higher estrogen levels correlate with greater sensitivity to stress on memory tasks. (1/22)
Electrical fields bad.
Heny Lai and Narendra Singh at U. Washingon have established that prolonged
low-level exposure to electrical fields damages the DNA in rat brains. Many
engineers and scientists have protested that the level of the fields to which
people are exposed, even when in a "high-field" activity like using
a hair dryer, are so low that the electromagnetic effect should be negligible.
Lai and Singh agree, and propose a mechanism involving action on within-cell
free iron and consequent free radical effects. Providing rats with specific
antioxidents (a vitamin E analog or a nitric oxide synthase inhibitor) blocked
the DNA damage effect, substantially confirming their hypothesis.
The mechanism is the same in rat brains and ours; unlike some
rat studies, there's no hesitation in inferring we face the same hazard. What
it means: Don't spend a lot of time standing next to high-powered electrical
devices (electric space heaters, microwaves, toasters, hair dryers, cyclotrons),
don't leave the space heater on all night in your bedroom, especially if pregnant.
And (SBrunning is now your Mom) - eat your fruits and vegetables. (2/20)
Caloric restriction works for humans.
This isn't much of a surprise, since it works for a bunch of other mammals,
but Luigi Fontana and collegues at Washington University of St. Louis examined
18 people who'd been on a CR diet for an average of six years and they were
healthier on pretty much every index. What this means for runners is less clear
- artificially reducing caloric intake when burning at a high rate results in
bonking (at best) or more serious disorders (anorexia, bone loss, depression).
Nonetheless, of interest.
Additional info: There were 18 people
in the study, 15 of them men, who on average had been on the CR diest for six
years. Ages ranged from 25 to 82. They took in just over four-fifths the calories
that the controls did ("controls" = regular people with regular diets).
Complex carbs accounted for 46% of their caloric intake. Their body fat was
9% (with that age ranged, the expected average for a 50-mile-per-week runner
would be 12%. For more on the diet, check here.
As an aside, it's possible that the benefits for many of
the higher-protein, lower-carbohydrate diets have nothing to do with insulin
response or ketosis as much as with caloric restriction, since people tend to
eat many fewer total calories when eating elevated levels of protein and fat.
Original research reported in Proc. National Academy
of Sciences (vol.101, p. 6659); from New Scientist (Apr 24-30
2004). (Additional material from Science Vol 304 p. 514) (4/27)
Men, women, love, and the Olympics.
In 1999 Donatella Marazziti of U. Pisa found the neurotransmitter serotonin
dropped below normal levels in people newly in love (as well as in people with
obsessive-compulsive disorder.) Now she's shown that levels of the hormone testosterone
go down in men and rise in women for couples in the love-struck phase. "Men,
in some way, had become more like women, and women had become like men. It's
as if nature wants to eliminate what can be different in men and women. because
it's more important to survive [and mate] at this stage." This is an unexpected
finding, since there are multiple studies showing that testosterone level rise
in men with frequent sexual activity (which as those who have been madly in
love know is an entertaining part of the madly-in-love phase.) Marazziti's follow-up
found that with the same couples, after a year or two, still in love but no
longer madly in love, hormone levels returned to normal. (Original research
in Psychoneuroendocrinology.) (All-time great journal name.)
In related research, Andreas Bartels of University College
in London used fMRI to watch blood flow in the brain and found that when the
newly-in-love look at images of thier beloveds, the neural circuits associated
with critical social assessment seem to partially shut down. (Neuroimage.)
Please note the above confirms earlier investigations reported by
Percy Sledge (Mussel Shoals, 1965).
Bottom line for athletes: if you're a female Olympic hopeful, fall
madly in love. If you're a man, hey, might as well for it - true love beats
the Olympics every time. (5/10)
Women and iron. ScienceDaily
summarizes a study published in the American Journal of Clinical Nutrition (2004;
79:437-43) that found the surprising result that "among women who are not
anemic, only those with tissue-iron deficiencies can benefit from taking iron
supplements." "Supplementation makes no difference in exercise-training
improvements in women with low iron storage who are not yet tissue-iron deficient
or anemic," says Thomas Brownlie, the first author of the study and a Cornell
doctoral candidate in nutritional sciences. Iron deficient anemia decreases
work capacity because less oxygen can be carried to the muscles. The simple
inference is, getting iron up to the right levels will improve this. And in
previous work, the same Cornell scientists found mild iron deficiency reduces
endurance, and that iron supplementation improves exercise training, seeming
to reinforce the idea.
Apparently not. It's tissue deficiency, not 'merely' liver deficiency,
that benefits from supplementation. This appears true even at levels below anemia.
What does this mean? How do you know whether you're tissue-deficient?
There is a test - serum transferrin receptor concentration - or you can find
out post facto - take iron supplements and if your endurance improves,
you were tissue-deficient. Be aware that iron supplementation takes a long time
to have an effect - six to eight weeks - and that too much iron is hard on the
liver. (5/20)
Mitochondria. Perhaps not the most urgent
news you'll read today, but biologically the most unexpected. (Yes, even more
than pool plyometrics). Mitochondria are the little engines inside our cells
that allow us to process oxygen and carbs into energy. It's long been held that
we inherit our mitochondria only from our mothers. Hundreds of papers have been
written based on this belief; if you've heard of "mitochondrial Eve,"
the deep ancestor of all living humans, it's based on this.
Turns out it's wrong. Even more amazing, wrong on two
levels – we can inherit mitochondria from our fathers, and the mitochondria
in male and female 'germ cell' (sperm and eggs) can exchange DNA. (Mitochondria
have their own DNA, distinct from ours, though what "ours" means is
pretty fuzzy here.) No-one knows how they do it yet, or how common it is, or
what the effects on reproductive and evolutionary biology will be. But your
ability to use oxygen at the end of a 5K may come from both your mom and your
dad. (5/24)
Sex, stress, and free radicals.
Just-published research provides supporting evidence for the "DNA repair"
hypothesis about why there's sex. Evolutionary theorists have a problem with
sex - it reduces the pool of reproducing organisms. (If you have 100 people,
50 men and 50 women, you can kill 49 of the guys and the reproductive capacity
of the overall group doesn't change. This is a prime reason why when it comes
to sex, men behave as they usually do and women behave as they usually do.)
The standard explanation for sex has been that it allows gene mixing and adaptation
- fitting better into your environment. But many researchers believe that doesn't
make sense. Most mutations are bad, and if you survived long enough to reproduce
in a world that changes slowly, the best strategy should be to try to replicate
yourself exactly. The opposite of sex.
An alternate view is that sex is good for DNA repair: offspring
of sexual unions are healthier and more parasite-free than those of asexual
reproduction. New research strongly supports this view by showing that increasing
the DNA-damaging free radicals in the internal environment of algae causes them
to switch from asexual to sexual reproduction. Their little algae pheromones
go crazy. Excellent work by Aurora M. Nedelcu and collegues.
What does this have to do with running? Intense exercise releases
free radicals within our systems. Since sex is a pretty old invention
in evolutionary terms, the inference would be that the same response to free
radicals as exists in algae probalby exists in some form in us. Yow!
More info here.
(6/11)
Why we age as we do. The short sentence
version! Life uses energy. Life persists across time by reproduction. Genes
are what control and direct how a living organism can use energy and reproduce.
(Don't get snagged on genes "controlling" and "directing"
- it's just shorthand. There is no nature versus nurture tension - it's always
nature and nurture together.)
That was the history of life on earth. In people, our genes
have to make a tradeoff - go for broke and burn up the energy young to enhance
the chances of reproducing, or start out slowly so you'll be around to make
sure your offspring survive, thrive, and reproduce in turn? The second one sounds
better, but if others go for broke and you don't, you risk losing completely
in the reproduction department. That's the worst possible choice for your genes
to make. On the other hand, if you go completely for broke but none of your
offspring survive... Uh-oh. Nature demands a compromise between short-term and
long-term goals. It's caled pliotropy - partly you go for broke early (young
women gain fat on their breasts and hips during peak reproductive years, it
migrates to butt and thighs later) - partly you conserve (women live about 10%
longer than men probably because grandmothers have a much bigger effect than
grandfathers on the survival of grandchildren - even today, even in the 'first
world' nations.)
Just to make sure you don't underestimate how complex the
tradeoff is, some of your genes do go for broke and other genes try to save
up. Some of your genes actively sabotage other of your genes to get
thier way.
There you have it. If you are or were agile, flexible, cheerful,
and energetic when young, hey, exactly the traits that make you attractive to
the opposite sex and increase your chances of reproducing. And if you are or
will be cranky, stiff, and slow as a geezer, well, your great-great-grandparents'
genes made the evolutionary tradeoff and the waiter's still bringing
the bill.
SBrunning - the only running website, probably,
to discuss pliotropy. (6/7)
High protein diet reduces likelihood of pregnancy.
High protein intake is associated with high levels of ammonium in the female
reproductive tract, which is in turn associated with breakdowns in imprinting
(expression of critical specifically female genes), in implantation, and in
fetal development. Studies so far have been with mice, so it's not definitive,
but they're the same genes working the same way. Not, however, recommended as
sole means for birth control. (More at ScienceDaily.)
And: a single act of unprotected sex is more likely to result
in pregnancy than previously thought. The European
Soc. for Human Reproduction and Embryolgy reports results indicating that
without being consciously aware they were doing so, women who actively did not
want children still engaged in sex more at their periods of maximum fertility
than any other time. (6/30)
Milk builds good bones. Science
News reports research by Jillian Cornish of U. Auckland with the unexpected
finding that lactoferrin, a protein found in cow's milk (and breast milk as
well, most intensely in colostrom), binds to cell surfaces of osteoblasts. Osteoblasts
are the cells that build new bone. Lactoferrin not only stimulates bone growth,
it interferes with osteoclasts (cells that reabsorb bone into the bloodstream)
and partially blocks apoptosis (cell self-destruction) in osteoblasts.
If you're female, especially a young female, a female from a family
with a history of osteoporosis, or a female with osteoporosis, you should go
have a milkshake right now. A malt
is even better. If you're nursing, or a pregnant, or either of those and
a family history of osteoporosis, you should jet over to McConnell's for a malt.
Or two.
Original research published in Endocrinology.
(7/20)
Yogurt and arthritis. Arthritis is an inflammatory joint
problem, and in a recent rat study yogurt containing live cultures - our little
pals lactobacillus bulgaricus - prevented arthritis symptoms developing
in animals given arthritis-inducing injections. The study authors hypothesize
that the effect in the intestine is to neutralize other bacteria that might
act as triggers for the self-directed immune response that causes arthritis.
If you have arthritis, or a family history of arthritis, adding
yogurt to your diet may alleviate or eliminate it. Make sure it has live cultures
- it will say 'live' or 'active' in the ingredient list. Original research published
in J. Nutrition (August 2004), reported in Science News (166:100).
(8/19)
Gene delivery to skeletal muscle. U. Washington researcher
Jeff Chamberlain and team have found a way to engineer a non-reactive
virus to carry the key dystrophin gene needed to hugely improve the condition
of Duchenne muscular dystrophy sufferers. A faulty version of the gene
causes the disease, which causes wasting of muscles. The ability to deliver
the gene to the skeletal muscles - and nowhere else - and to avoid undesirable
'side' effects, is a major breakthrough. Though a long way from clinical
trals - the demonstration was a mouse study, not human - this is thrilling
news for those with muscular dystrophy and for their families.
Chilling news for clean track and field, though. The biochemistry
of lactic acid buffering and elimination is fairly well-understood, and there
are candidate genes identified that may determine our differering rates. When
the genetic detective work is done - it will be - it's inevitable that someone
will use this to cheat. It will be extremely difficult to detect. There will
be no markers in either blood or urine; even with a muscle biopsy it may not
be possible to distinguish. Original research published in Nature Medicine (August
2004), reported in Science News (166:84). (8/19)
Lactic acid as nourishment. In a report appearing in the 20 August Science, Peterson et al. report results indicating that lactic acid actually aids, rather than hinders, muscular performance under stress. Analysis to follow; in the meantime, you can blame depolarized calcium ion channels resulting from accumulation of extracellular ionized potassium when you get tired. (8/24)
PPAR-delta and free fitness. Ron Evans and team at
the Salk Institute, researching obesity, discovered that altering genes
that produce the protein PPAR-delta resulted in one-third the weight
gain in mice fed a high-fat diet as compared to controls (regular mice).
What was unexpected was the swtich in muscle fiber types. The engineered
mice doubled the amount of slow-twitch muscle. As a result, without any
additional exercise, their endurance increased 92% when compared to controls.
Original research in Public Library of Science Biology (vol 2, e294);
reported in New Scientist.
We asked Annie Toth, a PhD candidate in molecular biology,
her opinion. She checked the original paper in PubMed; GlaxoSmithKline,
the pharmaceutical giant, is already testing a PPAR-delta enhancing drug in clinical
trials with people. Her comments:
"I'm somewhat morally opposed to making drugs that
target PPAR delta... and not just because athletes could (and would) abuse them.
There are so many obese people in our country, and obesity-related diseases are
becoming out of control. So what are we going to do? Spend billions of dollars
to make drugs to treat people with these diseases? Why not spend the money on
after-school programs that encourage kids to develop healthy exercising habits?
As the authors of the article acknowledge, manipulating PPAR-delta has the same
effects as exercise." (9/8)
Diets. Recent research on the Atkins approach (oversimplified, "avoid
carbs") suggests that it's not ketosis and altered burn rates, it's simply
that people eat less. (Fewer calories = weight loss.) David Ludwig and team,
at Children's Hospital in Boston, published interesting research in The
Lancet (364:778) on a controlled study in which rats were fed equal numbers
of calories, the differences being in the proportion of low glycemic-index
(GI) and high-GI carbs. At the end of the study period, the rats in the two
groups weighed roughly the same. However, the high-GI group had 71% more body
fat, and 8% less muscle. In addition, higher levels of triglycerides (linked
to heart disease) were found in the high GI rats. Ludwig points to independent
evidence that high insulin levels promote food uptake by fat cells, while low
levels promote use by muscle cells. Ludwig and team think the effect of the
low GI diet is to moderate insulin levels, while high GI diets cause spikes.
Whether or not this is the cause of the observed effects, nutritionists
agree that, unlike Atkins, a low GI diet will do you no harm. Low GI diets have
been used for a number of years to control Type II diabetes.
An earlier post on kid's vision and low GI diets is here;
for a general intro to low GI diets, try here.
(9/10)
Heart elasticity. As we age, typically our heart muscles become less elastic. This means less blood enters the heart between beats, forcing the heart to work harder. Research conducted by Ben Levine at Presbyterian Hospital tried to separate how much of the stiffening is due to aging and how much to lack of exercise. His small study compared 12 late-60's male runners (30M+/week) with the same number of men of similar age but less than three 30-minute exercise sessions a week. Both groups were compared to thirty-year-olds whose exercise was similar to the sedentary seniors. Besides the expected lower resting heart rate, the running geezers heart elasticity was nearly the same as the kids'. (Original research published in Circulation [110:1805], reported in New Scientist 25 September p18.) (9/27)
Nursing mothers and their babies make the women around
them horny. Research led by Martha McClintock at U. Chicago
found that exposure to nursing mothers and their babies increased sexual
desire in other women. The mechanism is chemosignalling - chemicals
emitted that may not be perceived consciously as odors but affect mood
and behavior nonetheless. Original research in Hormones and Behavior.
Two notes. One, most likely this research was possible
because the six-person research team was entirely women. For those who recall
when a woman with a PhD was exceedingly uncommon, a full reserach team like this
signals a profound and positive shift. Second, no research was done with men.
There's nothing better in the world to hold than a newborn; there must be some
effect on men. Guess we'll have to wait for a not-quite-all-male research team
to investigate. (11/13)
New brain cells develop during alcohol abstinence. Here. No comment. (11/13)
Fat guys dumb. But maybe not fat women. Actually, this is about mice: Chiou Lih-Chu provided a high-fat or normal diet to her subject animals, then examined their brains at what would be, for a person, middle age. Male mice who'd lived on the high-fat diet showed far less responsiveness in the hippocampus than the lower-fat controls (the hippocampus is key to the ability to learn). Correspondingly, the high-fat males were slower to learn new behaviors. Unexpectedly, females on the high-fat diet were similar to the lower-fat females and the lower-fat males. (Soc. of Neuroscience annual meeting, reported in Science News 166:302.) (11/11)
Partially hydrogenated &tc. These are called trans-fats and are frequent additions to foods to preserve shelf-life. Ann-Charlotte Granholm reported at the Soc. of Neuroscience annual meeting that trans fats given to rats caused them to be up to five times less capable of learning than rats given equal amounts of fats as soy oil. The trans fats rats' brains showed signs of damage to the hippocampus. If you've been using margerine instead of butter, time to reconsider. (Reported in New Scientist, 6 November 2004.) (11/7)
A little too ironic. Exposure to low levels of the organic pesticide rotenone gives monkeys Parkinson's, indicating it may have the same effect on people. Rotenone is a natural insecticide found in some garden products and still used by some organic farmers. Monkeys given rotenone show the same neurodegeneration human Parkinson's victims do. Research by Timothy Greenamyre of Emory U. (Original research presented at Soc. of Neuroscience annual conference; reported in New Scientist, 6 November 2004.) (11/7)
Genes. Yannis Pitsiladis at U. Glasgow has found that elite Ethiopian runners are significantly more likely to have a combination of four Y-chromosome gene variants than other Ethiopians, including those from Arsi (where Ethiopian distance runners originate). Pitsiladis points out that there is no one gene for distance running, though, and that the differences are not overwhelming. Pitsiladis and team hope to study Kenyan runners to see whether the same pattern is present. Original research in Human Genetics, reported in New Scientist 27 November 2004. (11/29)
Fat or pain = smaller brains. In an interesting
finding, long-term obesity for women results in shrunken brains, and
chronic pain has the same effect. Deborah Gustafson of Sahlgrenska University
Hospital in Goteborg, Sweden, led the study on obese women. Brain atrophy
was significantly more prevalent in obese women than in their leaner
peers. "Obesity is related to ischemia, hypertension, and cerebrovascular
and cardiovascular diseases. These conditions contribute to an unhealthy
vascular system, and therefore, to a higher dementia risk. Obesity may
also increase the secretion of cortisol, which could lead to atrophy." While
the study was entirely women, it seems plausible that the same effect
would be found in men. Original research in Neurology, reported
in ScienceDaily.
Meanwhile, Vania Apkarian found that both men and women
with chronic back pain could experience brain shrinkage of up to 11% - an effect
that corresponds to up to 20 years of normal aging. Apkarian hypothesizes that
the observed effect could be the result of overuse atrophy - the constant pain
stimulation effectively causing literla burnout. Original research published
in J. Neuroscience, reported in ScienceDaily.
(11/29)
Chocolate returns. Also testosterone for women
and antioxidents for men. Latest:
Chocolate
supresses coughing. (Many members are now thinking, "well,
I'm not coughing right now, but preventive medicine is best,
so...")
Chocolate
is also associated with increased sexual interest/activity for women
Testosterone
supplementation for women is associated with greater interest
in and satisfaction with sex. Women naturally produce testosterone,
just as men naturally produce estrogen. Principal investigator Angelique
Flöter Rådestad worked with women who'd had
their ovaries removed; the overaies produce about half a woman's testosterone.
However, her findings most likely generalize. (Taking testosterone
is of course against the rules for competitive athletes, but the levels
Ms RÃ¥destad was measuring and supplementing to bear almost
no relation to those used for competitive advantage by cheating athletes
- one See's candy every other day compared to a ten-pound block of
chocolate every morning.)
Low
levels of antioxident
supplementation for men, but not for women, is associated with
lower cancer rates. Why this difference should exist is not known.
The study was substantial - 7 1/2 years, over 13 thousand people, so
it is not likely to be an artifact of study design. Original research
in Archives of Internal Medicine, 22 November. Serge Hercberg,
M.D., Ph.D., was the study leader. (11/23)
We evolved to run. Or: Why you have a big
butt. A just-published review in Nature proposes that distance
running was a critical element in our evolution.
Before citing the specifics, an aside. Evolution is not
a theory, despite some school boards. Darwin's explanation of evolution is a
theory (according the Ernst Mayr, five conjoined theories), but evolution itself
is a massively-documented fact of biology. (Darwin's theories are nearly-universally
accepted within biology, by the way; his theories are to evolution as Newton's
or Einstein's theories are to gravity, that is, a well-tested explanation of
an observable fact and a source of prediction for new facts.)
Dennis Bramble and Daniel Lieberman, authors of the paper,
describe a number of characteristics:
Long
legs. Compared to other primates, we're leg freaks. It's probably not coincidental
that long legs are associated with grace.
Short
arms. Again, compare to other primates, proportionally. We have short,
weak arms.
Large
leg joints. Suitable for absorbing and dissipating impact shocks during
running.
A
particular development of the inner ear. If this seems equally suited
to 'merely' standing on two legs, imagine standing on your hands and
then being able to run and jump over uneven surfaces while maintaining
equilibrium.
Big
butts. Our butt muscles are massive compared to other primates; measurement
of usage shows they're little-used in walking and standing, far more
in running.
Big,
springy Achilles tendons. These, like the buttocks, are little-used
walking or standing, but critical to running (as many know to their
sorrow).
Hairlessness
and sweat. We are especially good at heat dissipation – useful
for prolonged exertion. Hairlessness is another characteristic associated
with physical attractiveness.
SBrunning may be biased, but it is an appealing proposal: it
explains a number of different adaptations that are not otherwise obvious. Great
work. Original research reported in Nature (432.345-352, 2004). (11/18/04)
Don't wash your hair. And particularly don't wash your kids' hair. Stuff commonly added to shampoos - methylisothiazolinone (MIT) - causes baby rat brain cells to be stunted. U. Pitt Med School principal investigator Elias Aizenman says, "...our results thus far suggest there is potential that everyday exposure to the chemical could also be harmful to humans. I would be particularly concerned about occupational exposure in pregnant women and the possibility of risk to the fetus." Presented a few days ago at the Cell Biology annual conference; more details here. (12/10)
Exercise doesn't work for everyone. Claude
Bouchard of LSU has found that exercise just doesn't work for some people.
Bouchard put 742 people from 213 families through a 20-week endurance
training program. The subjects had not exercised regularly for the previous
six months. It isn't surprising that some people benefitted more than
others - it is surprising that some didn't benefit at all. For example,
while the average gain in VO2 max was 17%, those who responded best gained
40%, but some didn't make any gains at all. Similar results were found
for resting heart rate, blood pressure, and insulin sensitivity.
Regular readers of this site know that our response to
training is regulated by which of our genes turn on and off. Bouchard measured
gene expression for insulin sensitivity. He compared the eight volunteers who
showed the largest gains with the eight who showed the least. In the muscles
of the top eight, 51 genes were expressed at double the levels of the non-responders,
and 74 genes at half the level.
Bouchard's work reinforces the sense we all share that
as endurance athletes we've been privileged by our genetic luck. (Original research
at the Australian Health and Medical Research Congress, reported in New
Scientist 4 Dec 2004.) (12/8)
Stress ages us more quickly. The folk wisdom that stress accelerates aging has been confirmed at the DNA level. Telomeres are the "ends" of DNA strands. They shorten with each cell division, so they're a good marker of aging. Elissa Epel at UCSF tested 58 women, aged 20 to 50, checking self-reported stress levels and telomere length. The high-stress women's were shorter, corresponding to between 9 and 17 years of cell aging. (Original research in Proc. National Academy of Sciences, reported in New Scientist, 4 Dec 2004.) (12/8)
Women prefer women, men go both ways. Stephaine Goodwin (Indiana) and Laurie Rudman (Rutgers) found that women tended to prefer the company of other women, while men, though varying widely as individuals, did not show an overall pattern of preference. The sample size was good (just under 400 people) but because the sample was comprised entirely of college undergraduates, the results may be skewed. In particular, men who liked sex liked women more, but the young age of the subject population is such that there could have been a significant number of men who were not only not sexually active, but either had never been, wished they were, or both - in any of these cases, more hesitant about expressing a preference for men due to insecurities about perception regarding sexual orientation. Be interesting to see the study repeated with an older population. (Original research published in October issue of J. Personality and Social Psychology, press release here.)
Cherries and diabetes. Cherries seem to influence insulin production, and may reduce likelihood of or severity of diabetes. Anthocyanins, a coloring pigment (and much, much more), increased insulin production in mouse pancreatic cells by 50 percent. This is good. Nice therapy, eating cherries. Both tart and regular seem to be effective; no news on black cherries. (Original research to be published in 5 Jan 2005 J. Agricultural and Food Chemistry, press release here.)
Mitochondria and thinking. Work at MIT (where Martino's dad teaches neuroscience) found that mitochondria - the endurance athlete's favorite cell-dweller - reconfigure themselves within brain cells to generate the necessary power for synaptic transmission and reception, the foundation of learning and memory. Very nice piece of work. Morgan Sheng was the principal investigator. Speculation (not from the researchers): since endurance athletes seem to show unusual clustering of high-education individuals, and since it is known from some small-scale studies that endurance training improves mental acuity, then have Sheng et al. found a key mechanism? (Or are high-mitochondria-count people drawn both to study and to endurance athletics?) (Original reserach reported in 17 Dec Cell, press release here.) (All items reported in ScienceDaily.) (12/22)
Exercise may not be as much a cause of lowered risk
of heart disease, diabetes, etc., as has been thought. It's
long been known, based on experimentation and observation, that exercise
reduces risk of heart disease and diabetes. Researchers at U. Michigan
took a founding population of rats and bred them selectively in two groups,
one for high aerobic capacity, one for low. At the 11th generation, they found
that the low-aerobic-capacity rats had more markers for cardiovascular disease,
insulin resistance, and more abdominal fat - on the same diet and exercise
program as the high-capacity rats.
This confirms the common-sense observation that some rats - and people
- have more athletic talent than others. However, it also raises the question
of what causes what - specifically, do people genetically predisposed to aerobic
fitness, and by implication to have lower risk of heart disease and diabetes,
also spontaneously exercise more? Instead of exercise causing reduced risk
of heart disease, the genes that cause reduced risk also cause exercise? We
humans are biased to think dichotomously - either a causes b or b causes a.
In this case, it looks like each causes the other. Original research in Science (21
Jan issue). (1/26)
Nothing sexier than big brains. A team led by Bruce Lahn at Howard Hughes Medical Center looked at 214 genes than influence brain development in mammals. They found the gene mutations that led to bigger, more powerful brains spread far more rapidly in proto-humans than in other mammals. One of Darwin's profound insights was 'sexual selection' - the mechanism by which within-species mating competition works. Darwin saw that nature accepts many adaptations that do not confer survival advantage. The peacock's tail is a vivid example. Sexual selection refers to the effect of mate choice within a species - if females prefer males with characteristic X, regardless of whether it aids survival or not, then that characteristic will spread among males. Similarly for male preferences among females (though for most mammals female choice is much more important). The rapid spread of big brains - even though biologically big brains are very 'expensive' - is strong evidence that people preferred mates who were funny, smart, thoughtful, sensitive, and so on - all the things big brains, and only big brains, can bring. (Original research in Cell, December 2004; reported in ScienceDaily.) (1/12)
NEAT, weight, and fitness. NEAT stands for
non-exercise activity thermogenesis - which means burning calories when
you're not working out. In some elegant work by James Levine et al.,
self-described couch potatos were instrumented for ten days. Some were
naturally lean, others mildly obese. The difference between the leans
and the mildly's in non-exercise spontanteous physical activity was about
2 1/2 hours a day. That's time the leans were up moving around, doing
this or that, fidgiting - engaged in non-systematic physical activity
- that the corresponding mildly obese were sitting.
The jury is still out on whether the growing obesity
epidemic is the result of more and higher-glycemic food or less activity, though
some data from Britain suggest the latter. The mechanisms that influence propensity
to fidgit aren't known - hard not to think there's a substantial genetic component
since it tends to run in families. On the other hand, since it is an epidemic,
environmental factors have to play a major part in the large-scale trend.
Nice experiment: remove television completely from some
significant number of households and see what happens to activity levels and
weight. Meanwhile, get up. (Original research: J. Levine (and many others), Interindividual
variation in posture allocation: Possible role in human obesity. Science,
vol 307, 28 January 2005.) (2/3/05)
Natural stoner babies. Endocannabinoids are the built-in version of marijuana. (Psychoactive drugs don't work unless there's something already built in, also psychoactive, for them to mimic or trigger.) Turns out breast milk is high in anandamide, an endocannabinoid. Happy baby! (2/8)
Green tea and humor. Researchers at Kao Corp (Japan)
found that the equivalent of about four cups of green tea a day resulted
in up to 24% increase in endurance performance. The proposed mechanism
is stimulation of fatty acid use for energy during exercise. Interesting
stuff, but there's reason to be somewhat skeptical. The rate of improvement
being so high suggests that not-particularly-fit subjects began the study.
(Do you believe that with no changes in your training other than drinking
green tea, you'd be able to run an extra 6+ miles past the end of a raced
marathon?) Still, green tea is good, so... Something to consider. Original
research reported in the online edition of the American Journal of
Physiology-Regulatory, Integrative and Comparative Physiology, 27 January 2005 (from ScienceDaily).
Meanwhile, at Texas A&M, David Rosen and collegues
found exposure to a 15-minute comedy video caused subjects who subsequently filled
out a questionnaire to show significantly higher levels of hope. The proposed
mechanism here is the competitive inhibition of negative thoughts with positive
ones, which sounds nice and is so vague as to be kind of amazing. (Think about
trying to come up with a non-circular definition of "negative thoughts.") But
what the heck - maybe negative thoughts are like art and (famously) pornography
- we know them when we see them. In any event, these two guys walked into a bar
- the third guy ducked. Original research in Intl. J. Humor Research. (2/11)
Play and exercise reduce Alzheimer's, especially if you're a genetically engineered mouse. Mice can be gene-engineered to develop the amyloid build-up typical of Alzheimer's disease, an extreme loss of mental capacity that stikes some older persons. U. Chicago's Sam Sisodia led a team in a comparative examination mouse brains from groups of such mice living in either boring or play-oriented environments. He found the play-and-exercise environment greatly reduced the buildup of the amyloid plaques typical of Alzheimer's. A nice thing about this particular research is in avoiding the chicken-and-egg problem - are people who like exercise and intellectual challenge already less likely to get Alzheimer's, or does the activity itself have a preventive effect? Because of the young age of the mice and the nature of the experimental setup, the conclusion is that the exercise and cognitive activities cause, rather than simply correlate with, the reduced amyloid build-up. Separate research (C. Lyketsos, Johns Hopkins, to be published in Am. J. Epidemiology) indicates that exercise may reduce Alzheimer's risk by as much as 50%. So go out and run around and play. (Original article, J. Marx, Science vol. 307, p 1547) (3/15)
Green tea, apples, and oysters. Green tea first. According to Roger Thornley et al., epigallocatechin, green tea's anti-cancer component, works by blocking dihydrofolate reductase. That enzyme is necessary for tumor cells to grow - so green tea is good - but did you notice the "folate" in there? Unfortunately, the same green tea component reduces folic acid levels - and reduced levels in pregnant women can lead to birth defects. (Original publication in Cancer Research, reported in New Scientist, as are the next two items.)
Apples, meanwhile, seem to prevent oxidation of LDL. LDL (low-density lipoproteins, a.k.a. bad cholesterol). LDL is only bad when it oxidizes, so... Nice that the research (by Chu YiFan) was done in apple-growing upstate New York (at Rod's alma mater, Cornell.)
As for oysters, are they an aphrodisiac, as folk tales claim? Well, they might be. They're unusually high in N-methyl-D-aspartate, which is a testosterone precursor. In a nice move for a food, they compared N-etc. levels with those found in rat brains, reinforcing the preference for oysters, if given a choice. Work by Raul Mizra of Barry University (in Florida), reported at the American Chemical Society's annual meeting. (3/29)
Zinc and kids' learning. Kids given supplemental zinc showed improved learning, with a linear effect -- meaning the kids getting 10 mg supplemental zinc learned better than the control (no supplement) group, and the kids getting 20 mg learned better than the 10 mg kids. The result is interesting because the control group was not deficient in zinc. (No comment on whether rubbing zinc oxide on kid's noses to prevent sunburn makes them smarter. While anecdotal, listening to surfers talk suggests not.) Research reported in Science News (5/8)
Preeclampsia and sucking air. If you don't know what preeclampsia is, you probably recognize Viagra. Surprisingly, they may make a good combination. Preeclampsia is a form of high blood pressure during pregnancy that can harm both mother and future baby. The vessels supplying blood to the fetus are restricted in preeclampsia, reducing blood flow to the baby and potentially causing long-term harm, or even death. Viagra to the rescue. Viagra works by enhancing the effect of nitrous oxide (somewhat locally), which in turn enhances blood flow. In work with (what else?) rats, George Osol at Vermont C. Medicine found that sildenafil citrate (Viagra) reduced or eliminated preeclampsia. Promising.
Sucking air: Lorrie Brilla of Western Washington U. made 22-year-olds suck air at 75% of maximum capacity, 60 times a session, five days a week, for six weeks. Compared to the beginning, the 15 volunteers (both male and female) could both put out 10% more peak power in an anaerobic (30 sec) session, and move 25% more air in a single breath.
This raises all sorts of questions: speedwork clearly trains the diaphragm to move air, but what percentage or part of improvements with speedwork could be attributed strictly to greater strength at moving air? Do, for instance, triathletes who while swimming or riding move to high levels of air transport gain as much benefit from speedwork as distance runners? (SBrunning knows for certain that at least some club members are speculating about crossover effects of this particular training on other, fairly specific, areas of their lives.) (4/23)
You're a total wimp. Recently Dean Karnazes and Pam Reed have been garnering press for their incredble feats of endurance, running continuously for up to 300 miles. Undeniably impressive. There's been a pretty solid wall of ego out there to accompany it, particularly from Reed, who is effectively a professional runner professing to be a full-time mom. But all of us have times when we think we're reasonably tough. So here's some context:
Picture yourself hiking roughly 60 miles in the mountains. Real mountains, climbing about 25 thousand feet, descending about 19 thousand. (As much as the most mountainous ultra in the US covers in 100 miles.) Solid hike. Now tune the picture to high elevation, say just under 11 thousand feet. Those climbs look more demanding. Now tune the picture again: if you're a man, put 93% of your body weight on your back. For a 150 lb. man, that's a 140 lb. pack. If you're a woman, you only carry 66% of your body weight. (125 lb. woman = 83 lb. pack.)
If you're really tough, double the distance and make sure you (barefoot) cross a 17,000' glacier on your way.
Oh. If you want to make it to the top 20 percent, men should carry more than 125% of body weight--a 188 lb. pack for the 150 lb. guy.
Daily life for Nepalese porters. To date, the most energy-efficient walkers in the world. Perhaps next fall at Nine Trails, all the guys should pick up two or three 60 lb. bags of concrete mix to carry; women get a couple of full five-gallon water jugs. To keep us all aware of where and how we live.
Original research by Bastien et al., in Science [308, p 1755]. (6/25)
More sex. Yep, the athlete's favorite topic. Two recent results of interest:
Birth control pills may result in permanent partial loss of interest in sex. Research by Goldstein and Panzer of BU focused on SHBG, a sex-hormone binding protein that blocks the action of testosterone (which despite its rep is produced by females as well as males and is critical in female interest in sex). Women on the pill had levels seven times higher than women who'd never taken it; and those who'd taken the pill but then went off still retained levels three or four times higher. Goldstein: "There's the possibility it is imprinting a woman for the rest of her life." (American Assn of Clinical Endocrinologists annual meeting, reported in New Scientist).
It ain't a "lifestyle choice." Geneticists Barry Dickson and Ebru Demir at the Inst. of Molecular Biology at the Austrian Academy of Sciences found that a small change to a fruit fly gene -- a small change -- caused female fruit flys to reject male sexual attention but to actively seek and initiate sexual relations with other females. (Reported in LA Times.) (6/3)
Aging and oxidative stress. It might not be oxidative stress. This is news: the current working hypothesis about aging is that oxidative damage to mitochondrial DNA (mtDNA) is responsible for aging and eventually, in the absence of other causes, death.
If "oxidative stress" is meaningless to you, think about how running magazines (and health magazines, and doctors, and supplement makers) urge you to take anti-oxidants. An anti-oxidant is something that prevents or moderates oxidative stress.
In this week's Science, Kujoth et al. find that aging (in mice, of course) is associated with higher mutation rates in mtDNA, but the result is not from oxidative stress. It appears to be from increased levels of cell death. Increased cell death means tissues simply run out of working cells.
It this is confirmed in subsequent studies, it will be a major change in our understanding of the mechanisms of aging. Meanwhile, go short on anti-oxidant manufacturers.
Original research in Science, Vol 309, pp. 481--484. (7/21)
Walking and running efficiency. Human locomotion is amazingly efficient. Andy Ruina and Manoj Srinivasan of Cornell found that by modeling human forward movement simply as a pendulum action, walking and running gaits 'emerged' from the mathematics of the model. It's not surprising that our movement is energy-efficicent, but it's a nice connection that walking, running, and pendulums all conform to the same simple physics. Check it out for yourself here. (9/25)
Pregnancy, herbs, babies, health. A few recent findings:
A survey and meta-analysis of herbs and vitamins commonly used during pregnancy has just been published by the MDs at Motherisk. The researchers reviewed the scientific evidence for the safety and efficacy of a number of commonly used herbs and vitamins. The Motherisk site is a good resource; a summary of the findings is available here.
Chemicals in the environment 1: There's consistent evidence that chemicals in the environment can "gender-bend" human babies. Earlier this year, research found that phthalates in the environment result in boys with smaller penises. Now, in a Canadian community adjacent to a chemical plant, in the four years between 1999 and 2003, male/female birth rates shifted radically from the norm, to nearly two-thirds girls. A likely though yet-to-be-confirmed culprit is hexachlorobenzene.
Chemicals in the environment 2: Pieter Sauer and team analyzed blood samples form mothers and from umbilical cords. The unexpected finding was that chemicals uses as antibacterials, flame retardants, detergents, pesticides, artificial musks, and plasticizers (including phthalates) were all present in the umbilical blood. Except for the antibacterials, the concentrations were lower in the umbilical blood, but Sauer concludes, "Apparently every chemical that is introduced into the environment on a large scale can enter the unborn child." (Reported in New Scientist, 10 Sept 2005 p.6.)
Post-race extra virgin olive oil. According to Paul Breslin et al., writing in Nature (437:45), extra virgin olive oil contains oleocanthal, a COX-1 and COX-2 inhibitor: "Structurally, it's not similar, but pharmacologically it's very similar" to ibuprofen. About one and a half ounces a day acts as a low-dose anti-inflammatory. (9/11)
Kind of strange. The LA Times reports (Tues 9/7) that Americans are getting our bioflavinoids (great little antioxidents) from... red wine (44 milligrams/glass)? Bananas (76 mg)? Corn (48 mg)? Nope--coffee, which was reported to have about 1300 mg per 8-oz cup. Yow. (9/10)
Science: Babies fix their mother's brains. "Yeah, that's for sure," some Moms may be thinking. Gavin Dawe and Xiao Zhi-Cheng found that in mice (our trusty little experimental pals), fetal stem cells that stray into the bloodstream ("microchimerism") can pass the blood-brain barrier, settle in the mother's brain, and repair damage, becoming neurons, astrocytes, and oligodendrocytes. (Science tip: There is no conversation that isn't spiced up by mention of astrocytes.) If this result holds up in humans--there's no reason to think it won't, since microchimerism is already well-known in people--the promise of stem-cell repair of brain diseases like Alzheimer's becomes much more plausible. And for you moms, isn't it nice to know you wonderful little one's gave you some brain repair cells before they used up ten times as many growing up? (Original research in Stem Cells DOI:10.1634, reported in New Scientist 20 Aug 2005.) (8/28)
Hey, he might be yours! In a meta-analysis of studies dating from 1950 to 2004, medical researchers found that up to one in twenty-five children are not the biological children of the fathers who think they are. (The official medical term is 'paternal discrepancy.') Don't worry, guys, a key finding was that this only applies to other people. (Original research by Bellis et al., J. Epidemiology and Community Health vol. 57). (8/26)
Don't use it, but get it back. Fred Gage and colleagues at the Salk Institute found that sedentary, elderly mice (human equivalent = 70), when given a chance to exercise, reinitiated the process of neurogenesis--which means they started growing new brain cells and got smarter. J. Neuroscience vol 25 p 8680. (9/26)
Healthy kids. Research by Emory's Chensheng Lu has found that only 15 days of organic food can clean out the continually-resident organophosphates that are endemic in American children (and adults). In a commentary, Tufts Med School's Doug Brugge says, "in a population that does not have other pesticide exposures, eating organic foods virtually eliminates organophosphate-pesticide burden in... children." (Original research in Environmental Health Perspectives, reported in Science News.) (10/1/05)
ATP in a new role. Adenosine 5'-triphosphate, our little energy-carrying molecular pal, has been found to act as the neurotranmitter responsible for relaying sensations of taste to the brain. An unexpected finding; not perhaps Oswald Avery discovering that DNA carries genetic information, but a surprise nonetheless. Props to Sue Kinnamon of Colorado State.
Leucine may aid muscle retention with aging. Research led by Lydie Combaret and Dominique Dardevet at the Human Nutrition Research Center at Auvergne found that (in rats) supplementing diet with leucine aids protein synthesis after eating, resulting in reduced rates of muscle loss with aging. Short version: there's reduced inhibition of a necessary but should-remain-balanced muscle degradation process with aging, and leucine seems to counteract this. Read more here; or here. (12/4/05)
Vegans in SUVs. Pamela Martin and Gidon Eschel, both of U. Chicago, compared the typical American diet (28% of which comes from animal sources) with a vegan approach from the perspective of atmospheric carbon emissions. They found that the difference amounted to roughly 1.5 tonnes of emissions per year. (One tonne = 1000 kg = ~2205 lbs.) That is, vegans' diet generates, on average, 33 hundred lbs less carbon dioxide emissions each year. That's for a single person.
By contrast, the difference between a standard sedan and a hybrid is about one tonne a year. So if there's exactly one of you, you're better off going vegan than parking the Volvo wagon and getting a Prius. Of course, if you're part of a family, the difference is magnified. Interesting and unexpected. What you drive matters less than what you eat. (And, Prof. Martin got her doctorate at UCSB.) (1/5/06)
Guys--your sons (and grandsons) are what you eat. SBrunning has been predicting for some time that epigenetic inheritance will be big--name-in-lights big! (As far as we know, this is the only English-language running site published in Santa Barbara County to make this claim.) Marcus Pembrey and colleagues found through two distinct lines of evidence that diets and smoking habits of fathers influenced (in one case) the health of sons and (in another) the longevity of grandsons. Animal studies show the effect, and it has been known for a while that daughters and granddaughters could be so influenced, but this is the first evidence of epigenetic inheritance on the male line. (Original research in European J. Human Genetics, reported in New Scientist.) (1/7)
Caloric restriction yields younger hearts. Research at Washington University (St Louis) led by Luigi Fontana found that people who had followed a coloric-restriction diet for an average of six years had hearts that resembled much younger hearts than an age- and gender-matched set of peers. In particular, the heart elasticiy was superior. It's been known for some time that in mice and rats, caloric restriction results in a 30% increase in lifespan and lower rates of cancer and heart disease. The caloric restriction diet appears to reduce "secondary aging," e.g., hardening of arteries, diabetes, hypertenson, etc. As far as is (so-far) known, there are no down sides to caloric restriction--except for being hard to do. Original reseach in the 17 Jan J. American College of Cariology; here for caloric restriction info. (1/13)
Keep that microwave plastic out of the microwave. Bisphenol-A is used for microwave plastics, dental sealants, baby bottles, linings of metal cans, and lots of other things. It acts like estrogen in the body, and testing finds it to be common in people's bloodstreams. Angel Nadal of U. Miguel Hernadez (Elche, Spain) found that it also contributes to insulin resistance, a precursor to diabetes.
Insulin regulates blood glucose--having even insulin levels is good. Insulin resistance, where cells don't respond to insulin correctly and blood glucose drops, is a bad thing; there are no positives about insulin resistance. The surprise in Nadal's study is that levels considered safe by the US Environmental Protection Agency led reliably to insulin resistance in mice. The mechanisms in mice are essentially the same as those in humans (insulin level management is evolutionarily old and is "conserved" across species.)
Take-home message (so to speak): get rid of the plastic baby bottles and plastic microwave containers. (2/10)
Red wine, long life, and don't get your hopes too far up. Fish given resveratrol, a component of red wine, lived up to 60% longer than a control group of similar fish. It's a reasonable assumption in this case that if it works with vertebrate fishes, it will work with other vertebrates, including us. This is believed to be the first instance of a single molecule prolonging life. Research conducted by Alessandro Cellerino of the Italian Institute of Neuroscience.
Down side, our digestive systems destroy resveratrol, so only about 5% of what we consume is actually be usable. To achieve the same levels as had such dramatic effects in fish, we'd need to consume around 72 bottles of red wine a day. This could influence training. (2/15)
Exercise through pregnancy for smart kids. Hippocampal growth was strongly enhanced in mouse pups born to exercising mothers, as compared to non-exercising controls. The hippocampus, besides having a cool name, is directly involved in learning and memory. What's interesting here is that the behavioral attributes of the mother influence the genetic expression of her offspring. One wonders what mediates the transmission? And--does it work in humans? Don't know, but it'd be the way to bet if you were pregnant. Original research in Proc. Nat. Academy of Sciences, vol. 103. (3/11)
Beer is good. Wine and green tea suppress inflammation in white blood cells; thanks to Deitmar Fuchs et al (International Immunopharmacology) we now know beer does too. Not only that, but beer blocks depletion of tryptophan, from which the cheerful neurotransmitter serotonin is made. Beer even contains some tryptophan. Further research may be required. (3/11)
Sex, food, love, and more sex. The latest:
Sex with someone else (besides yourself) 400% more fun. (This might be conditioned by who the someone else is, current marital status, etc.) After orgasm, prolactin is released into the bloodstream. Prolactin makes us feel sated (by countering dopamine, which is released during arousal). Brody and Kruger report in Biological Psychology that after partner sex to orgasm, prolactin levels are 400% higher in both men and women than after masturbation. Interestingly, elevated prolactin levels have been clinically found to be associated with erectile dysfunction in men, which may explain the physiology of men's recovery period.
Being hungry makes you smarter. When you're hungry, your stomach produces the hormone ghrelin, which the hypothalmus (in your brain) interprets as, hey, time to eat. Ghrelin also binds to the hypothalmus (another part of the brain), which is associated with learning and memory. Tamas Horvath and friends at Yale injected mice with extra ghrelin and found they significantly outperformed normal mice in lab tests for mouse learning and memory. Their brains had roughly 30% more brain cell connections, as well. (Original research, Nature Neuroscience.)
You really do love each other. Harvard's Christakis and Penn's Allison found that risk of death in the elderly increases when a spouse becomes seriously ill. It has been known that the death of a spouse increases the risk of death in the surviving partner; it's now clear that in the US, serious illness, particularly if disabling, also increases the risk. Original research in the New England Journal of Medicine.
And, why is there sex at all? After all, evolution is utterly indifferent and ruthless. In a population of 100, if all were females and all reproduced asexually, there would be a tremendous advantage in numbers. With only 50 females available to carry offspring, the sexual reproducers should be completely swamped. Indiana's Paland and Lynch studied water fleas, who switch back and forth from sexuality to asexuality, and provided evidence supporting what evolutionary biologists have long suspected, that the advantage of sexual DNA recombination is that it cleans up bad mutations. Said another way, females use males as a kind of genetic mop to clean up their offspring's DNA before sending them out into the world. Ah, the dignity of manhood. Science 311:17 Feb 2006. (3/4)
Science: Lactic acid is your pal. Work by a Berkeley team has found that enduracne training results in the body's adaptation to using lactic acid as a fuel on par with stored carbs and blood sugars. Strange but true: here. (5/10)
Baby spacing, lowered risk of Alzheimers Two new topics:
Columbia researchers looked at 67 studies, covering 11 million births, and found that spacing babies' conception 18 months to 5 years apart was associated with healthier babies. If you're in the planning stage.
According to another Columbia study, people who chose a Mediterranean diet suffered less incidence of Alzheimer's than there peers. "Mediterranean" diets are characterized by fresh fruits and vegetables, fish, and unsaturated fats, with little beef or whole-fat dairy. (5/2)
Cherry juice and muscle soreness. A report to appear in the British Jounranl of Sports Medicine found that fresh cherry juice was markedly more effective than a placebo mixture in reducing muscle soreness after exercise, and in addition reduced loss of strength when exercise was terminated. Kind of odd, but pretty cool. More info here. (7/23)
Fat makes you good. Anthony Civitarese from Pennington Biomedical Research Center in Baton Rouge, Louisiana found that adiponectin, a fat-generated hormone, is critical to mitochondrial health. (Mitochondria are the cuddly little symbionts inside our cells that generate energy.) In a slight departure from much of what we report, this is actually true of humans as well as mice. Fat is not your enemy. Original research in Cell Metabolism, reported in Science Daily. (7/6)
Antioxidants in food work; in supplements... ... the evidence is weak. There are a couple of good clinical studies showing a positive effect, but then there are a lot more showing no effect at all. But (a) not all antioxidants are the same (alpha tocopherol is not the same as alpha lipoic acid), and (b) "hybrids" like our local FRS, where the antioxidants are integrated with sugars and some stimulants--well, the jury is out on long-term health benefits. It's hard to measure telomeres and cell repair damage. There's even evidence that antioxidants are bad. The only known high-reliability route is through healthy food. Eating well is (drum roll) good for you. For a summary on the current state of knowledge, try New Scientist.
Despite the claims made for pomegranate juice, most of the top five antioxidant foods are beans. (8/27)
Men and women. We reported recently that men and women are different. Recap: a mouse study, but we share about 99% of our genes with mice. Male and female brains are the most similar (about 15% difference in gene expression), but liver, muscle, and fat show 55% to 72% difference. (Wow.) Importantly, the differences are not primarily in the maintenance genes, but in those that control function.
The new part. When the researchers removed ovaries and testes (do not try this at home), which produce the bulk of the testosterone and estrogen that flow through our bodies, most of the differences disappeared. Our bodies are incredibly sophisticated. Patient, skilled, and tenacious science, amazing result. (8/27)
Sunscreen and autism. Work by Kerry Hanson at UC Riverside found that not only did sunscreen sink in too much to be useful after around an hour, but once it did, it actually increased the ROS (damaging free radical) levels. If you're going to use it, once an hour. Hats are your friends, too. For autism, a study of 318 thousand men found that those who conceived over forty had six times the rate of autism in their offspring than men of 30 or less. (Which may mean a genetic or epigenetic origin.) From the Archives of General Psychiatry.
Proteomics and the timescales of training. Most runners have read that the basic mechanism of training is adaptation to stress. But what is 'adaptation'?
Stress causes differential gene activation. Our genes code for proteins--we're made of proteins--and if you want to change the mix, whether of mitochondrial density or muscle composition, you have to persuade your genes to express more of the proteins you want, and less of the proteins you don't want. The 'mix:' cells generally contain around 20 thousand different kinds of proteins, 100 million or more protein molecules per cell. Running causes the mix to change. If you think of your training as triggering gene expression, the time it takes between training and fitness effects makes sense. So does the consequence of training volume. (It's now known that fever doubles lymphocyte production by the immune system--tempting to wonder whether the increased core temperatures of hard running may have a similar effect, and that this is a key signaling mechanism in response to training. But that's pure speculation by a non-biologist.)
Fitness comes from gene expression. Patience and persistence. (11/11)
Signature. Most have had the experience of seeing someone running from too great a distance to distinguish facial features, sometimes even gender, but knowing without effort who the person is. Recent research suggests that our ability to recognize idiosyncratic movements is central to our ability to recognize other people. It's not only motion that enhances perception (though of course it does--thwarting exactly that is why deer are able to stay so extraordinarily still); it's movement specific to the person. Next time you spot someone you know, take a sec to appreciate the incredible, sophisticated processing your mind is giving you with no work at all on your part. Here's a cool video on how little information we need to make sense of movement. (Perception research by Steede & Hole, 2006: Repetition priming and recognition of dynamic and static chimeras. Perception, 35, 1367-1382) (11/23)
Yogurt: key to top performance? In an unlooked-for result* lactobacillus acidophilus, the yogurt and "probiotic" bacterium, boosts synthesis of receptors for opioids and cannabinoids in gut cells. (Morphine and marijuana work because we have opioid and cannabinoid receptors in our brains; our pals the endorphins and endocannibinoids bind there.) Eating yogurt boosts pain thresholds by 20% for abdominal pain. Especially if you're a rat; results for humans aren't known, but likely an effect is still there. Would higher abdominal pain thresholds improve competitive performance? (Original research: Nature Medicine, reported in New Scientist 16-22 December 2006.)
* "Unlooked-for" is of course wrong--somebody looked, and pretty closely to detect such specific protein syntheses. It's only that some results follow on large bodies of widely-known prior research, but some are less intuitive--if (as we imagine) opiods and cannibinoids modulate the perception of pain, why should the gut have receptors at all? Evolution's designs are more strange than our imaginations can fabricate. (12/16)
Running with your nose to the ground. Introductory biology books drone about how weak humans are, as animals--not as fast as the cheetah, strong as the elephant, bad eyes, etc. This is, of course, absurd. We're gigantic, for one thing. (You can probably name all the animals that are larger than we are, but you're unlikely to name all of the 900 thousand species of beetles, which are far less numerous and varied than bacteria.) The human hand is a good candidate for the pinnacle of evolved functionality.
Cal's Noam Sobel and Jess Porter found that people can follow scent trails like dogs, too. We use differences between nostrils to localize, similar to binocular vision or sound localization using our ears, and we get much better with practice. Compared to dogs, though, we are really bad at moving forward with our noses close to the ground. (Original research in Nature Neuroscience 10.1038:nn1819.)
Speculation on divorce rates. Birth control pills diminish women's sense of smell. Seemingly, whether we're conscious or not, we use smell to identify compatible partners. (We evolved to prefer mates whose immune systems complement our own.) One wonders whether there's a difference in failed relationships between those begun with a masked sense of smell and those not. (12/26)
Biology: Time of month. UCLA's Martie Hazelton took full-body pictures of thirty women, 18 to 37, one near ovulation (peak fertility), and one at fertility low-point. She then had volunteers judge from the pictures when the women were trying to look most attractive. The volunteers picked the high-fertility pictures (59% above random, or roughly eight out of ten times). All of the women in the study group described themselves as in committed relationships with men. An unrelated but connected study, Christine Garver-Apgar of U. New Mexico found that, in a group of 48 heterosexual couples who'd been together at least two years, in those pairs between whom the major histocompatibility complex (MHC) is most similar, the women were most likely to secretly sleep with other men--and preferentially during/around ovulation. (Degree of difference in MHC is believed to correlate with the health of biologically shared children.) We believe we know why we do what we do, especially in something as central to our lives as our principal relationship, but the evidence doesn't much care about our belief. (Original research published in Hormones and Behavior vol 51, p 40 and Psychological Science vol 17 p 830, respectively.) (1/23)
It is what you think. Training triggers gene expression, which causes fitness changes, which changes training. And of course, mood and attitude influence gene expression, which influences mood and attitude. Thought triggers action triggers gene expression triggers thought. You can jump in anywhere in that loop.
Harvard's Alia Crum and Ellen Langer studied hotel maids. It's tough and tiring work. Crum and Langer told half the test cohort that the work they were doing was good exercise, reinforcing this message with handouts and wall posters in break rooms. The other half of the test cohort was given no such instruction. The two groups were matched for the work they did. At the end of the short study, the women in the "exercise" group had, on average, lost two pounds, dropped their blood pressure 10%, dropped their body fat percentage, and had other measurable changes indicating improved health as compared to the control (no instruction) group.
Crum is planning a longer study, but this is an amazing demonstration of the placebo effect--perhaps better described as the productive interplay of expectations, beliefs, gene activity, and physical health. (Original research published in Psychological Science Feb 2007.) (2/13)
Science: Sex, burgers, and coffee. And free-playing kids.. Latest news:
US men (born between 1949 and 1983) whose mothers ate a lot of beef have lower sperm counts. Ironic, since in the 50's and 60's eating beef was strongly associated with manliness in popular culture. (Human Reproduction 10.1093)
Your partner is above average in looks, intelligence, warmth, and sense of humor--at least, that's true for 95% of the people interviewed by Wellesley's Faby Gagne. Maureen O'Sullivan (USF) found that while both men and women acknowledged lying to potential partners about past sexual experience, women in particular rated themselves as being more honest than other women.
Coffee repairs liver damage. Increasingly, the primary source of liver damage is excessive weight, even exceeding alcohol. The bad thing is, you can damage your liver without being aware of it until you're far gone. The good is, coffee repairs roughly 30% of non-alcoholic liver damage, and up to 80% of alcohol-caused damage. Arthur Klatsky, of Kaiser-Permanente, says, "I haven't the slightest idea what the mechanism is."
The January issue of the journal Pediatrics includes a summary report of multiple studies of the effects of free play on children's well-being and physical, cognitive, and emotional growth. Let 'em play. (4/3)
Skin protection and sunscreen. SPF ratings represent levels of protection from UVB--ultraviolet radiation in the "B" range (320 to 280 nanometers), but accumulating evidence suggests that melanoma (the worst kind of skin cancer) it more sensitive to UV in the "A" range (400 to 320 nm). Older sunscreens didn't block UVA at all; newer ones do, but there's no standard rating for UVA protection. In addition, some manufacturers use physical blockers like zinc oxide and titanium dioxide, but to avoid visibility very small particles are used (nanoparticles) and the effect on the skin and any absorption rate are not yet known. Take-home message: reapply your sunscreen every 45-60 minutes, and generally wear something that covers your shoulders, nose, and for guys, tops of ears. Not paranoid, but aware. (7/4)
Self-sacrifice involving chocolate. German researchers found that heroically forcing themselves to eat a quarter-ounce of dark chocolate a day lowered systolic and diastolic blood pressures of hypertensive persons by 3 and 2 points, respectively. That's enough to case a five percent reduction in heart attacks (if spread through the whole population). Of course, you may not be hypertensive, but why take chances? Also, the people who did this didn't gain any weight. You can read more here. If you won't do it for yourself, do it for others. (7/4)
Why we yawn, and why it's contagious. Andrew and George Gallup of SUNY Albany propose that yawning cools the brain and thereby enhances alertness, and that yawning contagion functions to enhance group vigilance. Generally, nasal cavity blood vessels cool blood in the head, and cooler blood is associated with heightened alertness. The Gallup's protocol had students watch films of people yawning. Test conditions were varied to include cold packs and warm packs on the forehead, instructions to breath only through the mouth (including a subset with a nose plug), only through the nose, or normally. Cool foreheads and nose-breathers didn't yawn; fifty percent of the mouth breathers and warm foreheads did. Finally, a plausible hypothesis about one of those commonplace but fundamental mysteries. (Original research in Evolutionary Psychology 5:92.) Yawning in the face of danger may not be such a bad idea. (7/4)
Bisphenol A and your long-term health. A team of 37 led by Missouri's Frederick vom Saal analyzed seven hundred research papers on bispehnol A (BPA) and found that BPA concentrations in human tissue were about ten times higher than the EPA current limits for human exposure. Vom Saal believes that, because BPA affects the hormonal system, it is likely to have effects at much lower concentrations than even the EPA standards.
BPA gets into our systems by leaching from plastic containers and bottles; and from linings of cans. For parents of young kids, it's easy to find BPA-free sippy cups--although if you get bottled water, it's likely a polycarbonate plastic, which is made with BPA. For bikers and runners, though, none of Nalgene, Ultimate Direction, and GOLITE had any acknowledgment or mention of BPA on their web sites. (Nalgene is a polycarbonate; Korean-made Ultimate Direction a high-density polyethylene, which is better.) National Geographic has a nice info site; and a little buying advice. Exercise care. (8/15)
Science: Do you really want to excel as a distance runner (guys)? Craig Atwood, MD (U Wisconsin, Madison) hypothesizes that the transformation of Lance Armstrong from one-day winner to true endurance athlete came with the removal of a cancerous testicle (which happened before his amazing string of Tour de France victories). Having a testicle removed increases production of gonadotropin hormones (while not reducing overall testosterone production). Higher levels of gonadotropins are associated with higher levels of fat metabolism, and for endurance athletes, particularly at longer distances, the ability to burn fat as fuel is strongly correlated with performance.
While this may be the simplest--and legal--surgical improvement in distance-running capacity available, one suspects that few will choose this route. (9/3)
Intervals and an unexpected effect. Kazushige Goto (U Tokyo) and colleagues compared two exercise regimes, a regular 60-min workout, and the same total duration and intensity but broken into two thirty-minute sections with a 20-min rest break separating them. Their result (J. Applied Physiology, June 2007): meaningfully higher levels of fat burning in the "broken" workout than the continuous.
The study subjects were active 25-year-old men, but they were not trained endurance athletes, and the output level for the study was moderate (60% HR). Would be interesting to see this replicated with competitive athletes. Still, of great interest for those who enjoy self-experimentation. (9/3)
Ketone bodies. These are produced in small quantities by the liver when other fuel is no longer available, as a last-ditch effort to maintain the brain (ketone bodies cross the blood/brain barrier and a metabolized more efficiently that fat). In work led by Kieran Clarke (Oxford), rats fed ketone polymers ran 30% faster and 30% farther over five days of trails than rats fed fat or fed carbohydrates. it'll be a few years, but watch for these. Certainly they're unlikely to deliver that level of performance difference for trained humans--an eight-hour Nine trails runner is not going to run 5:36 based on a different energy bar--but this may be an interesting advance in exercise nutrition. (9/3)
Is this why bars are so loud? John Swaddle and colleagues (William and Mary) found that zebra finch females, normally strongly bonded to a single mate, became equally likely to mate with a previously-unknown male when in the presence of loud noise. Do humans do something similar? (9/7)
Flavinoids and endurance. A commonplace for endurance athletes when training for a goal race is to slip slightly over the hard-to-see edge from training fatigue to illness. This isn't always bad--there are more than few marathoners whose PRs came after an illness-induced "forced taper"--but there are better ways to rest before a race.
David Nieman of Appalachian State gave 40 male cyclists either a gram of quercetin (a flavionoid) or a placebo every day for three weeks, while training the living crap out of them (including a three-day series of 3-hour max-capacity time trials). As Nieman put it, "By the time they were done, they were just wasted." Two weeks later, nine of the riders in the placebo group had chest infections, compared to only one in the quercetin group (Medicine & Science in Sports and Exercise, 10.1249). In addition, the quercetin influences modulation of antigens (molecules that stimulate the immune system) (J. Applied Physiology 10.1152). Earlier research, sponsored by FRS, had shown that quercetin, coupled with other antioxidants, could boost elite cyclist performance by 3%. Nieman has not found any adverse reactions to boosting quercetin consumption.
Note that the "average American" is believed to take in roughly one-tenth of a gram a day, and if you're reading this, you're unlikely to have the same diet as the average American. (9/8)
Tea. Green tea can revive near-dead brain cells, at least in a test-tube; and in a short-term study with mice, the specific ingredient under study (epigallocatechin gallate) boosted dopamine levels significantly even when about half the mice's dopamine-producing cells had been lost. Potentially good news for Parkinson's sufferers; interesting generally.
In human testing (not mice!), tea was also found to be more effective than coffee for stimulating alertness. Theanine, in tea but not in coffee (or much of anything else) was found, when in combination with caffeine, to boost alertness in two different tests, moreso than either caffeine or a placebo--or theanine alone. Nice example of combinatoric effects, where neither alone has the distinct effect but together they do. (This is why testing drugs is so difficult.) Coffee-drinkers, don't despair--this is a both/and, not an either/or. More on theanine. Results presented at the 4th Ann. Scientific Symposium on Tea and Human Health (reported in Science News, 172:206). (10/13)
Placebos to race faster?. Fabrizio Bendetti et al. (U. Turin) discovered that when exercising with pain, morphine can result in longer endurance. The surprise was that, for those who'd been dosed with morphine, during a second session (a week later) a placebo injection had the same endurance-enhancing effect. (A placebo is an inert substance that the subject believes to be an effective drug.) Placebos have been found effective in many domains, but this is a first. The World Anti-Doping Agency allows opiate painkillers during training, but not on the day of competition. Of course, since the placebo effect depends on the belief of the recipient, it's ruled out for high-level competitive athletes. Still an interesting finding. (11/3)
Science: Nitric oxide and blood flow. Tibetans living at 12 thousand feet and above have around half the oxygen in their blood as we do at sea level. Nonetheless, they're as active as we are. Blood oxygen levels are low enough that most MDs, encountering the measurements at sea level would prescribe supplemental oxygen. Cynthia Beall and team at Case Western found out how they do it.
It's simple: the Tibetans have twice the blood flow. Beall measured 88 Tibetans (living at 4200 meters!), compared to 50 controls in Cleveland (~200 meters). The key to heightened blood flow appears to be a full order of magnitude higher levels of nitric oxide in their blood. Beall believes that the nitric oxide acts as a vasodilator, allowing double the blood flow with the same heart effort. This is the second genetic adaptation discovered in high-altitude residents (see here). (Original research in PNAS 10.1073.) (11/3)
Hip Moms, smart kids. William Lassek (Pittsburgh) and Steve Gaulin (UCSB) analyzed data from the US National Center for Health Statistics, and discovered that, on average, women's waist-to-hip ratio correlated with their children's intelligence. Low ratio (big hips, narrow waist) yielded smarter kids. It's not just the fat, it's where it's stored--hip and thigh fat is converted more efficiently during late pregnancy and nursing than 'core' fat).
Don't jump to conclusions, though. For shape (contrasted with size), humans have far more sexual dimorphism ("different shaped-ness') that other primates, and women carry much more fat than female chimps, gorillas, orangs, and so on. (As well as more than men.) The obvious inference is that the fat is needed during pregnanacy and lactation to produce and nourish our gigantic brains (which are mostly fat). Skinny runner girls are likely to have as much native capacity to put on fat as their less-lean friends, but their activities burn it off--until third trimester or so (when sleeping generally becomes more appealing). If you're well-nourished and non-amenorrhic (when not pregnant), you're likely fine.
It's also good to remember the study used waist-hip ratio as a 'proxy' measurement for hip/thigh fat stores. A proxy measurement is a stand-in: "we don't know the actual fat ratio and distribution, so we'll use something we do know that's generally correlated." For a large statistical sample, this safely ignores difference in skeletal structure. But on a woman-by-woman basis, there's a lot of variation, and no-one is claiming that women whose pelvic bones are narrower have dumber kids. (Original research in Evolution and Human Behavior.) (Veteran's Day)
Breastfeeding. Fatty acids--human specific fatty acids that is. Gotta love 'em. Moffett et al. (King's College, London) looked at two groups, 1000 New Zealanders and 2200 British, specifically for the FADS2 gene, which codes for an enzyme we use in fatty acid metabolism. Ninety percent of us have the common variant; ten percent a less-common one. Moffett asked all participants whether they were breastfed, and administered IQ tests. She found that for those with the common variant, breastfeeding gave a 6.8 IQ point advantage, regardless of social class or the mother's genotype (which variant she carried). The fatty acids in breast milk are believed to be important for brain development, and the more common FADS2 gene is more efficient. Moffett believes this to be the source of the measured difference. (Original research in Proc. National Academy of Sciences.) (Veteran's Day)
Don't eat. Well, not great advice for runners, but B. Horne (Intermountain Medical Center) asked 515 older people being tested for possible hear disease about fasting. This is in Utah, and Mormonism calls for fasting one day a month. Of the sample, those who fasted had 39% better chance of a healthy heart than those who didn't. Interesting, but this is a near-perfect example of the kind of thing where taking it at face value is risky. People who can hold themselves to a lifetime of fasting once a month are likely to be disciplined, both in their lives in general and specifically in their diet. How much of the healthy heart is actually the result of the fasting, and how much the result of myriad other life choices and habits? Still, of interest: Horne cites animal studies showing that periodic withdrawal of food might re-sensitize insulin production, which correlates with lower rates of heart-damaging diabetes. (Veteran's Day)
"My choice, not yours". This is a touchy subject for some, but humans (us) are medium-promiscuous, compared to other primates (based on physiological evidence). One thing we've inherited from other mammals--since mammals have pretty much every possible variation on promiscuity--is in-utero female choice. This has been known from observational evidence for a while--female baboons, for instance, mate with multiple males, but their offspring tend strongly to be from one of those males, not a mix. Alireza Fazeli et al. have now identified the molecular mechanism by which females select which sperm they prefer (in the presence of sperm from multiple males). (Original research in J. Proteome Research Journal.)
SBrunning declines to speculate about practical application of this knowledge within the running community. (Thanksgiving)
Key mellowness protein identified. Running has been recognized as an antidepressant since Hans Seyle's groundbreaking work on stress in the 50's. Yale's Ronald Duman et al. have identified a gene in mice that seems to play a key role in mediating the antidepressant effect. VGF--which produces a nerve growth factor (also called VGF) seems to be the most prominent of the 33 genes Duman's team identified as being activated by exercise. Duman thinks VGF may lead to a new class of antidepressants, since the SSRI's (like Prozac) have proved to be effective only for limited durations, and have a number of undesirable side-effects (including suicide).
Lab science is designed to overcome "confounding factors"--the "everything else" that plays into any complex phenomena. We run with friends; we run outdoors; we run in the sunlight (sometimes); we run in beautiful natural settings; when we run regularly our bodies adapt with increased capacity, vigor, health, and sensual awareness. Generalizing a single protein as the key to the cascade of running's (exercise's) psychological effects is a large step. But you have to start somewhere. Depression is a serious and in some cases debilitating disease--one could speculate that our choice of running as an activity pursued sometimes to [umm] unusual lengths is a form of self-medication. SBrunning hopes the research carries forward to practical and positive application. (12/15)
Greenery is good for you. Jules Pretty and colleagues (U. Essex) wanted to know the effects of exercise environment on mental health. Their earlier work had found that level of effort appeared to be less important than we runners typically claim: fishing and horseback riding were as effective as running in elevating mood, reducing stress, and bolstering self-esteem when done in a rural/natural environment. Recently his team compared the effect, while running on treadmills, of presentation of four visual environments: urban and rural, pleasant and unpleasant. They included a control group as well, with "no" visual environment, e.g., the typical gym. They found what was expected, viz., rural/pleasant had the greatest effect at lowering blood pressure and improving psychological outcomes, urban/unpleasant the worst. Urban/unpleasant was worse than no visuals at all. Time to head for Ellwood or More Mesa. (12/28)
Cholesterol isn't as simple as you thought. Two recent drug tests on lowering LDL cholesterol (low-density lipoprotein, the bad kind, contrasted with high-density HDL) found that (a) the drugs did lower LDL cholesterol, and (b) it didn't do any good in protecting the heart. Speculation: over the next 20-30 years drug development will move away from the current "single agent" model to something much more in line with the systemic complexities of our bodies' actual workings.
Science, 2: A recent metaanalysis of medical publications found that "positive" results are much more likely to see the pages of a journal than negative or neutral results. You might think, so what? JAMA should publish studies about things that work, not things that don't. Unfortunately, these are often the same things. This is particularly true for anti-depression drugs--ten studies, one finds an effect, nine don't, and the singleton is published. Practicing MDs see only that antidepressants work. (1/18/2008)
Androgens not so bad. A just-published metaanalysis has found that elevated levels of androgens are not associated with higher risk of prostate cancer. For middle-aged geezer men (and, one hopes, their spouses) this is good news. (Androgens are male hormones, testosterone being the most famous. Note the women also produce testosterone, as men also produce estrogen.) Here's to the research team that established this: a plausible, intuitive hypothesis with a reasonable biological pathway has been disproved. Nice work. (01/30)
Why we tire. It's not the lactic acid. Research led by Andrew Marks of Columbia found results that account for the biochemical mechanism for muscular fatigue. It's the calcium channels. Muscle expansion and contraction is mediated by ion exchange, for which trace levels of calcium are needed. During exercise, metabolic byproducts build up (PKA-hyperphosphorylate, S-nitrosylate, depletion of phosphodiesterase PDE4D3 and RyR1 stabilizing subunit calstabin1--runners talk about this all the time, of course), the consequence being, the calcium channel loses efficiency and we get tired. Marks et al. confirmed this in both mice and people. Follow-on experiments with mice found that dropping an enzyme that prevents calstabin1 depletion significantly increased mouse power and stamina. This has been the Grail for physiologists for a while; great work. (Original publication in PNAS 105:6, 12 Feb 08; search "Remodeling of ryanodine receptor complex...") (2/13)
Zigzag. Research published in the Journal of Theoretical Biology found that the shortest way up a hill--measured in energy economy--is to zigzag. Mathematical modeling confirms intuition, and SBrunning gets to use, twice, one of the crown jewels of the English language. (2/24)
Science: Predator mathematics. And your cell phone. Barabási and González (Northeastern) looked at 100 thousand users' text messages over six months to plot their movements (as long as they moved enough to change towers). What they found was that even in daily life, driving around the roads, our movements can be described by a Levy distribution--same mathematics that matches predators' movements. But not prey. Nobody knows why the Levy equations match the movement distribution. Oddity of life. (4/4)
Antioxidants may suck. In a meta-analysis of the results of 67 studies, Danish authors found that taking antioxidant supplements didn't do any good, and in some cases were correlated with higher death rates. Oh, well. "Just eat well," is the recommendation. Press release if you'd like a little more. (4/16)
Baby boys, baby girls, and what you eat. Fiona Matthews (U. Exeter) and colleagues tracked the eating habits of 740 women before and through pregnancy. They found a strong result: for the third of the women on the highest-energy diets, 56% had boys, compared with 45% boys in the lowest-energy group. (Before making any inferences about which gender is "high energy," male fetuses are more fragile than female, so the extra calories may have helped them survive.) Women eating a bowl of breakfast cereal every morning had 59% boys, compared with 43% in the group that had one (or fewer) per week. Matthews acknowledges that no-one really knows why. (Original research in the Proc. Royal Society: Biological Sciences.) (4/27)
Carbon footprint. Christopher Weber of CMU found that going vegetarian one day a week was roughly equivalent to driving 1155 miles less per year. Food for thought. (5/11)
Easier uphills. Simone Schnall (U Plymouth) had subjects estimate the steepness of hills. People estimated 10%-15% less steep when they had a friend nearby, as compared to those who estimated alone. The warmer the friend, the less steep the hill (in the estimate). Asking subjects to think about close friends or family members was worth up to 20%. (Original research in J. Experimental Social Psychology April 2008.) (6/15)
Science: How much of a rush?. Addicts--characterized by compulsive behaviors--are known to be more impulsive than the norm, but it's been open whether impulsiveness follows or precedes addiction. For rats, Beldin et al. show that impulsiveness associated with reduced dopamine receptors in the nucleus accumbens predicts which rats will become addicts when offered cocaine.
Running qualifies as sensation-seeking (another addict characteristic), yet requires the opposite of impulsiveness. It appears to be addictive in those who self-stimulate with intense training. One wonders if an addictive effect of training is the sensitization of dopamine receptors? (Original research in Science, 320:1353-1355). (6/14)
Take care of your daughters. Lassik (Pitt) and Gaulin (UCSB!) looked the National Health and Nutrition Examination survey (US kids, aged 6 to 16, 4000 subjects) and found that the higher kids' consumption of omega-3 fats, the higher their scoring on cognitive tests. The effect was twice as strong for girls as for boys. Even further, they found that for girls, but not for boys, increasing consumption of omega-6's correlated with lower scores. The typical American diet has about ten times as much omega-6 as omega-3--omega-6's are in safflower, corn, and soy oils, and cottonseed oil is ~50% omega-6 with almost no omega-3. Further, there's only so much we can process of fatty acids, and "excess" omega-6 can push out omega-3. Something to be aware of for sons, and particularly for daughters. Here's ScienceNOW's summary. (6/29)
Unfair advantage. Sound isn't as fast as light (even by the vaguest notions of "fast") but we don't conventionally consider that a few feet make much of a difference regarding who hears what, first. But that turns out to be wrong for world-class sprinters and starting guns. Jesus Dapena (Indiana) analyzed Olympic reaction times for the sprints (100, 200, and 400) and found that the outer-lane delays we exactly what would be predicted by distance from the starting gun. In addition, our bodies react more quickly to louder noises, and the "loud gun" phenomena also has a measurable effect. The IAAF recognizes this and in normal international meets, athletes respond to speakers behind their blocks, with the starter's gun actually a silent triggering device. No so in the Olympics, though, where it really is the gun that starts the runners. (6/29)
Girls as competitive as boys. Just different. Joyce Benenson et al. (Emmanuel College) watched 87 four-year-olds, divided into same-sex groups of three. When given a single high-value object, the boys asked for it, tried to grab it, even chased whichever boy had it. The girls excluded the possessing girl from their clique, whispered behind her back, and even hid from her. Nice irony that the research was published in J. Animal Behavior (2008.01.0127). (6/29)
Cipro-family antibiotics. Maggie M. writes, "I took Cipro about four years ago while in marathon training, and 2 days after starting it, while on a tempo run, experienced sharp, debilitating pain in both my achilles tendons, almost simultaneously. I could barely walk. I read the insert, found out acute tendonitis was a 'rare' side effect, and called my medical group. The on-call doctor pooh-poohed me. When I spoke to my regular doc, he immediately took me off of it. It took about a week to resolve; I was lucky. I did more research on the 'net, and found out it has caused hundreds of cases of severe tendonitis and complete achilles tendon rupture in runners, who are particularly susceptible.
"On the few occasions I've had to take antibiotics since, I insist on an alternative to fluoroquinolone drugs. Our runners should all be informed about this very real hazard. According to the article, the FDA is not doing enough to publicize the dangers to physicians, so self-education is critical."
Learn more here. (7/13)
Men and women need different diets? Crickets were the study animals, so too early for generalizations. Alexei Maklakov, of the Evolution and Ecology Research Centre at the University of New South Wales, found that for both reproductive success and long life, males thrived best on a 8-to-1 ratio of carbohydrate to protein , while females did best with 1-to-1. Given free choice, both males and females picked a sub-optimal mid-way diet. While generalizing from crickets has to be cautious, the sex differentiation in physical investment in childbirth and child-rearing in humans is far more pronounced. Interesting to see what can be discovered about human diets in this regard. (Original reseach in Current Biology, reported on ScienceDaily. (7/21)
EPO testing. Short version: don't believe EPO results. People who didn't use EPO, ever, will be disqualified for EPO usage during this Olympics; lots of people who've used EPO will not be caught. Bizarrely, WADA (the international anti-doping authority) hasn't even released the test protocol for the CERA EPO "test" the Italian Tour de France cyclist was accused of failing. (For non-scientists, not publishing the protocol is Renaissance science--that is, about four hundred years behind the times.) (I exaggerate; it's how science was done up to around 1780-1790, so ti's only 220 years out of date).) (Roche, the pharm giant that makes CERA, tagged it for manufacturing and IP rights, which means it's uniquely detectable, which means that dopers will either detag it or use a different compound.) For the details, read this. (7/27)
Free fitness. The New York Times reports on the second generation of "supermouse" work done at Salk (Evans et al., Cell), of a pill that can produce fitness. Magic. AICAR... "resembles a nucleotide that prompts the production of an enzyme that activates the high-endurance genes." Given at high does to mice, even sedentary mice become more fit. Experiments to date on humans have found no effect, although the dosages have been much lower than those given to mice. Humans are not mice--although the mammal gene signaling is similar, we have very different kinds of metabolisms. No-one yet knows if high doses of AICAR will have a fitness-enhancing effect in people. (Current research focuses on heart patients with severely reduced capacity.) Clinical-grade AICAR is costly (~$120/gram), and for human-equivalent dosages, the cost would be thousands of dollars a day (according to the Times' report). Whether AICAR or other chemicals will work in people, how effective they'll be, and the consequences of decoupling exercise, which has myriad effects, including endorphins and endocannibinoids that affect mental health, from fitness--all yet-to-be-answered questions. (8/2)
Monogamy and endocrine happiness. Evolutionary biologists love prairie voles, because one kind is fully promiscuous and one is fully monogamous. After lots and lots of work, the RS3 334 section of the vasopressin gene seems to be the discriminator. So, Hasse Walum and friends (Karolinska Institute) looked at 552 heterosexual at-least-five-year relationships among their fellow Swedes. Men can have no, one, or two copies of RS3 334. What they found was surprisingly linear: more copies correlated with lower scores on a pair-bonding evaluation, lower likelihood of being married, and a higher likelihood of a marital crisis. (Original research in PNAS.) One wonders about the distribution in endurance runners, since there's a family resemblance between the characteristics associated (at least colloquially) with monogamy and with endurance training.
Meanwhile, yet new evidence that BPA messes with your endocrine system. Work at U. Cincinnati led by Nira Ben-Jonathan found that low doses, equivalent to what people are exposed to, raise the incidence of metabolic syndrome in human tissue. Metabolic syndrome is a precursor to Type II diabetes, coronary heart disease, and stroke. Be aware, particularly if you're pregnant or have small children. (9/12)
Health (and global warming) The "book" on diabetes is, if you're fat, your risk is much higher. Epidemiologists Duk-Hee Lee (Kyungpook Nat'l U., Korea) and David Jacobs (U. Minnesota) found that persistent organic pollutants (POPs) seem to be a key factor in diabetes. Epidemiologists (who study disease prevalence and causes) have been troubled by the rise of diabetes, and since being overweight is a strong correlation, the assumption "fat and lazy = at risk" has been standard wisdom. Which might result in most readers of this site believing they're exempt. Lee and colleagues used US data to find a strong correlation between six common POPs and diabetes, regardless of obesity.
If you eat meat (beef) and milk products, you're almost certain to have POPs circulating in your blood. More meat, more POPs. The global warming connection arises because beef and milk products are sky-high in carbon cost: in common estimates it runs four times higher than grains. The average American household generates about twice as much carbon emissions from food as from driving, and meat is the biggest culprit. Dropping beef for one day a week is enough to shave 1.5 tons of carbon emissions a year.
Whatever your dietary choice(s), minimizing POPs in your (and your kids') diets can only be good. (9/27)
Tea better than water for rehydration. Maybe, anyway. Carrie Ruxton et al (King's College) looked at tea-based rehydration in contrast to water, and found the antioxidants in tea conferred an advantage, without a concomitant risk of caffeine-based dehydration (a reputed effect for which they found no evidence). This is (presumably) based on earlier work, Ruxton had found that black tea conferred lower risk of heart disease (European J. Clinical Nutrition). The "water versus tea" study was paid for by the British Tea Council, though Ruxton claims independence (unsurprisingly). The health benefits apply even if the tea drinker does not have a British accent nor dress in tweeds. (Thanks to Garrett Headley for the connection.) (10/1)
Emergence. Normally, science entries here are about health, fitness, and well-being. This is not that, but it is such an extraordinary result it's worth conveying. "Emergence" is a simple idea: that there may be laws governing the interactions of parts that cannot be found in the laws governing the parts themselves. Non-scientist readers are thinking, "So... Duh." But there's a distinction that makes how important this is clear. It's one thing to say a sensible way to describe things on the relationship level is not the same as the chemical, or biological, or molecular level. Everyone agrees on that. It's an entirely different thing, though, to say that in principle you can't predict chemical interactions in terms of the constituent molecules. Cannot. Even if you were to know the molecular level perfectly, you can't.
It'd be insanely cumbersome to try to describe global climate in terms of atoms, for instance, but up to now a shared assumption among all scientists has been continuity: if you took enough time, and you were crazy enough to want to, you could do it. It'd be useless, but it'd be possible.
Mile Gu et al. (U. Queensland) have demonstrated for well-understood description of magnetism (an Ising model), you could know everything about the forces and still not predict what the atoms would do. In geek, "We were able to find a number of properties that were simply decoupled from the fundamental interactions." (More geek: the team demonstrated that the relationship between the levels is formally undecidable.)
If this result holds up, it will be the most significant limitative result of the beginning of the century. (10/19)
Mental toughness. Tony Vernon (U. Western Ontario) ran a questionnaire-based study of 249 pairs of twins. "Mental toughness" was defined as comprising a mix of control over life, commitment, confidence, and the ability to face new challenges. The result: 52% of mental toughness was genetic. That's a big number in context. Original research in Personality and Individual Differences.
SBrunning is somewhat skeptical. Some people can run to their physiological limit, others can't; which might be used as a sign of mental toughness for runners. (It appears there's a limit on the number of times it's possible to visit that limit, possibly associated with changes in the way cortisol uptake works in the hypothalamus.) That's a different personality characteristic than the "mental toughness" of the discipline of correct preparation; which is a different personality characteristic than separating how you'd like to train and compete from what's appropriate to your current life responsibilities and obligations. The trope "mental toughness" is so pliable it can mean whatever the speaker wants. The nurse showing kindness while changing a bedpan in the middle of the night, or the single parent who can be loving and patient day after day, night after night, for years on end--competing well in a staged athletic competition, with a known release at the end, doesn't seem so tough. (11/7)
Kick back, dudes. Yalies Douglas Befroy and sidekicks found that in men who run at least four hours a week, mitochondrial energy consumption at rest is 54% higher than non-running men. Same ATP production, so it's the running. (In contrast to a predisposition that leads to both running and higher resting metabolism.) Since mitochondria work the same regardless of sex, the result will hold equally for women (even if the exact measurement differs). So run. Then kick back and burn. (Original research in Proc National Academy of Sciences.)10/28)
Foot fetish. Melanie Scholz et al. (U. Amsterdam) found that shorter heels tend to better distance running. Specifically, the energy stored in the Achilles tendon is more efficiently delivered if the heel length is smaller. Stolz and team both built a mathematical model and measured professional runners on a treadmill, with measurements that were mutually reinforcing. (Results in the J. Experimental Biology.) (10/26)