A few weeks back, we highlighted new research on how exercise boosts autophagy in cells. In this week's post, we follow the effects on exercise at the cellular level again — focusing on how exercise can change your DNA. Researchers in Europe have found that exercise changes the DNA methylation in skeletal muscle cells in response to a bout of intense exercise.
DNA methylation is a biochemical process, in which a methyl group is added to the DNA and this reaction alters the gene expression pattern. DNA methylation often results in reduced gene expression or even gene silencing. In this research, scientists studied the cells in the skeletal muscle of healthy people after 35 minutes of high intensity exercise. They found that the promoter methylation was reduced exercise-responsive genes in these cells within 45 minutes of exercise. The alteration of promoter methylation was also dependent on the intensity of exercise. For the first time, researchers have shown how the DNA of muscle cells is altered in response to exercise. The onset of the methylation changes correspond with the daily recommended intensity by the CDC.
The scientists also tested the effects of caffeine on promoter methylation and found that exposing the cells to caffeine reduces DNA methylation. While one may be tempted to replace exercise by caffeine and obtain the same effects, the researchers warn that the amount of caffeine required to generate the same changes in DNA methylation pattern is a lethal dose.
There are many unanswered questions that come up — how long do the changes in DNA methylation last? Is there a memory to the process? And are these changes inheritable? The group is continuing its research in addressing these issues.