How Exercise Changes Our DNA - NYTimes.com
Stephen Williams stashed this in Exercise
The Karolinska scientists overturned that obstacle by the simple expedient of having their volunteers bicycle using only one leg, leaving the other unexercised. In effect, each person became his or her own control group. Both legs would undergo methylation patterns influenced by his or her entire life; but only the pedaling leg would show changes related to exercise.
The volunteers pedaled one-legged at a moderate pace for 45 minutes, four times per week for three months. Then the scientists repeated the muscle biopsies and other tests with each volunteer.
Not surprisingly, the volunteers’ exercised leg was more powerful now than the other, showing that the exercise had resulted in physical improvements.
But the changes within the muscle cells’ DNA were more intriguing. Using sophisticated genomic analysis, the researchers determined that more than 5,000 sites on the genome of muscle cells from the exercised leg now featured new methylation patterns. Some showed more methyl groups; some fewer. But the changes were significant and not found in the unexercised leg.
Interestingly, many of the methylation changes were on portions of the genome known as enhancers that can amplify the expression of proteins by genes. And gene expression was noticeably increased or changed in thousands of the muscle-cell genes that the researchers studied.
Most of the genes in question are known to play a role in energy metabolism, insulin response and inflammation within muscles. In other words, they affect how healthy and fit our muscles — and bodies — become.
They were not changed in the unexercised leg.
The upshot is that scientists now better understand one more step in the complicated, multifaceted processes that make exercise so good for us.
Clever experiment; unexpected result. Huge epigentics changes from just a bit of endurance exercise.
What's the net effect of changing muscle DNA?
Exercise induced changes to muscle DNA may be what causes all of the other known good effects of exercise. It is just interesting that these changes are possibly due to involved-muscle epigenics and not only indirect effects such as high pressure circulatory flush, using up glycogen, etc. Finding out that epigenic controlling methylization changes this much means that the effects could be more wide-ranging than already known. Additionally, since it is now known that some epigenic changes can be inherited, this has surprising implications.
Well once we determine what changes the exercise makes, could we figure out how to induce them independent of exercise?