Epigenetics—the study of changes in gene expression—has become a buzzword of late. Epigenetic experts suggest that environmental factors might have the power to overcome inherited traits, like a predisposition for type 2 diabetes. New research offers more support for exercise as one environmental factor that can alter gene expression.

The study, published in PLOS Genetics (2013; 9 [6], 1-16 (e1003572), looked at changes in methyl groups in the fat cells of 23 inactive men. DNA methylation is typically associated with gene repression. One of the study’s focuses was to learn how 6 months of regular exercise—three indoor cycling or aerobics sessions per week—would affect DNA methylation among the men.

Throughout the study, the men participated, on average, in 1.8 sessions per week, which resulted in DNA methylation in about one-third of each subject’s genetic makeup. Genes associated with type 2 diabetes and obesity were among those favorably affected.

“In summary, this study provides a detailed map of the human methylome in adipose tissue, which can be used as a reference for further studies,” the authors explained. “We have also found evidence for an association between differential DNA methylation and mRNA expression in response to exercise, as well as a connection to genes known to be involved in the pathogenesis of obesity and type 2 diabetes.”