Exercise, even in small doses, changes the expression of our DNA, say Swedish researchers, who have described for the first time what happens on an epigenetic level in fat cells when we undertake physical activity.
The genes in our DNA cannot be changed, but they have methyl groups attached which can affect how the genes are expressed - whether they are activated or deactivated. The methyl groups can be influenced in various ways, through exercise, diet and lifestyle, in a process known as DNA methylation. This is known as epigenetics, a new research field that in recent years has attracted more and more attention.
In the new study, the researchers investigated what happened to the methyl groups in the fat cells of 23 slightly overweight, healthy subjects aged 35 who had not previously engaged in any physical activity, when they regularly attended exercise classes over a six-month period.
Analyzing 480,000 positions throughout the genome, they could see that epigenetic changes had taken place in 7,000 genes (an individual has 20,000 genes). They then went on to look specifically at the methylation in genes linked to type 2 diabetes and obesity.
"We found changes in those genes too, which suggests that altered DNA methylation as a result of physical activity could be one of the mechanisms of how these genes affect the risk of disease," says researcher Tina Rönn, from Lund University. This has never before been studied in fat cells and the researchers say they now have a map of the DNA methylome in fat.
In the laboratory, the researchers were able to confirm the findings by deactivating certain genes and thus reducing their expression. This resulted in changes in fat storage in fat cells. "Our study shows the positive effects of exercise, because the epigenetic pattern of genes that affect fat storage in the body changes," concluded researcher Charlotte Ling, also from Lund University.
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Source: Lund University