Activate Your Lean Genes

You may not have been born with “lean genes,” but it turns out you can activate them with the right lifestyle changes, says a recent report presented at a conference hosted by the American Heart Association.

Researchers gathered data on more than 12,000 men and women—monitoring the effects that physical activity had on 32 genes that are linked to body mass index (BMI).

The researchers found that individuals who walked briskly for an hour every day reduced their genetic influence toward obesity by half. On the other hand, spending 4 or more hours doing sedentary activities (such as watching TV) increased that genetic influence toward obesity by 50 percent.

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What gives? Researchers didn't identify the exact mechanism for how the genes react, but they did call attention to the fact that both sedentary lifestyles and physical activity had independent effects on BMI.

This suggests, says Qibin Qi, lead study author and a research fellow at the Harvard School of Public Health, that both an increase in exercise and a reduction in sedentary behavior are necessary to reduce your genetic predisposition to obesity.

Your takeaway: It’s great to hit the gym, but that workout won’t help much if you spend the rest of the day vegging out on the sofa.

Interestingly enough, this isn’t the first study to find that healthy lifestyle changes can fire up those lean genes.

Findings published in the Proceedings of the National Academy of Sciences found that when 30 men made comprehensive lifestyle changes (such as improved nutrition, stress management techniques, walking, and psychosocial support), the new lifestyle actually changed the expression of more than 500 genes in only a 3-month period.

Therein lies a key distinction: You’re not changing the genes themselves. Instead, these improved habits change the expression of the genes, says Dean Ornish, M.D., lead study author and founder and president of the nonprofit Preventive Medicine Research Institute in Sausalito, California.

In his study, Ornish said, many disease-preventing genes were up-regulated (turned "on") and many disease-promoting genes (including those associated with cancer, heart disease, and inflammation) were down-regulated (turned "off").

“Obviously we cannot overcome everything, but what’s great about these lifestyle changes are you can change a lot of things that people once believed were not possible,” Ornish said.

Moral of the story: You’re not a victim to your genes. So get up, and get active.

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