[18/5 NOTE: I don't really understand this study. See the comments below -- and help out if you can!]
Researchers from the University of Rome just published a study in the journal BMC Physiology in which they analyzed blood samples from 10 recreational runners before and after completing a marathon (press release here). The chief finding:
Apoptosis, the natural ‘programmed’ death of cells, is arrested in the aftermath of strenuous exercise. Researchers… studied peripheral blood mononuclear cells (PBMCs), isolated from whole blood samples taken from people after finishing a marathon, finding that the balance between expression of pro- and anti-apoptotic genes is shifted after the race.
The idea that exercise helps your cells live longer has been in the news recently (see, for example, Gretchen Reynolds’ piece on telomere length in the New York Times a few months ago). This appears to be another piece of the puzzle — though a marathon is a pretty intense bout of exercise, so you have to wonder whether you’d get similar benefits from a shorter workout.
A must-read article for anyone interested in the interplay of sports and genetics (and for anyone who’s adamantly convinced that Kenyans and Ethiopians dominate distance running because they’re born to run), by Sports Illustrated’s David Epstein. The article is too good and too packed with info to summarize with a few pithy quotes — the fact is, it’s a very complicated area. But the overall message plays down the roles of genes:
Pitsiladis selected 24 gene variants most often associated with sprinting or endurance prowess and looked for them in the genomes of four men who have held the world record in the 100-meter dash and five who have held the world record in the marathon. What he saw was that based on those genes, the world-beaters are not genetic outliers at all. Pitsiladis analyzed the DNA of some of his graduate students for comparison and found that “a student of mine has a better rating for sprinting than the likes of an Asafa Powell or Usain Bolt.”
A decade ago, when Pitsiladis began to study elite athletes, his medical students would ask why East Africans dominate distance running, to which he would reflexively respond that their secret is in their genes. “But after 10 years of work,” he says, “I have to say that this is a socioeconomic phenomenon we’re looking at.”
Having read Epstein’s article, I was interested then notice this press release from the University of Utah this morning:
Researchers have long wondered why the people of the Tibetan Highlands can live at elevations that cause some humans to become life-threateningly ill – and a new study answers that mystery, in part, by showing that through thousands of years of natural selection, those hardy inhabitants of south-central Asia evolved 10 unique oxygen-processing genes that help them live in higher climes.
Of course, the Tibetans live at much higher elevation than Kenyans and Ethiopians do (and they don’t seem to be particularly good at running). Still, the study seems to suggest that many generations of living at altitude does produce changes that show up in your DNA. It would be interesting to find out whether East African populations living at altitude show any particular patterns for these 10 genes related to oxygen processing.