Change Lifestyle, Change Genes

3 Months on Ornish Diet Changes 500 Genes, Many With Anticancer Effects

Medically Reviewed by Louise Chang, MD on June 16, 2008
From the WebMD Archives

June 16, 2008 -- If you change your lifestyle, you change your genes.

You can't get different genes, but how you act can change how your genes act, report Dean Ornish, MD, and colleagues at the University of California, San Francisco (UCSF).

Ornish is a clinical professor of medicine at UCSF and also a diet guru who's been telling us for years that by improving our lifestyle we can prevent and even reverse many chronic diseases.

Now, Ornish is joined by UCSF professor and chairman of urology Peter Carroll, MD; UCSF prostate-cancer geneticist Christopher Haqq, MD, PhD; and others. The goal of this pilot study was to see whether the Ornish lifestyle could help 30 men with low-risk prostate cancer who chose not to undergo treatment unless their cancer got worse.

It's too soon to say whether the men's lifestyle changes kept their cancer at bay. But genetic analysis revealed profound differences in noncancerous prostate tissues in just three months.

More than 500 genes changed the way they worked. Genes with beneficial effects, including some tumor-suppression genes, became more active. Genes with deleterious effects, including some cancer-promoting genes, were switched off.

"It is absolutely intriguing this lifestyle change can have as much effect as the most powerful drugs available to us now," Haqq said in a news conference. "We medical oncologists are always looking for drugs that can do this. It is delightful to find that diet and lifestyle can have profound effects and work as well as drug therapies with fewer side effects."

Ornish says the findings may motivate people who think there's nothing they can do.

"People say, 'Oh, it is all in my genes, what can I do?' That's what I call genetic nihilism," Ornish said in a news conference. "This may be an antidote to that. Genes may be our predisposition, but they are not our fate."

Motivated by having prostate cancer, the men in the study went all the way with the  Ornish diet. They ate a low-fat, plant-based, whole-foods (minimally processed or refined foods such as whole grains) diet. They walked at least 30 minutes six days a week and walked at least an hour three days a week. Every day they did an hour of simple yoga-based techniques including  stretching, breathing,  meditation, and imagery. And they participated in a weekly support group designed to increase  intimacy and social support.

Whenever Ornish lays out his full program, he sees people's eyes glaze over. Most people are not going to be able to make this kind of a change overnight, if ever. But Ornish says it's silly to defeat yourself with an all-or-nothing approach. Adopting just the changes one can make, and making more changes only when you're ready, is a much more realistic path to health.

"People have a range of dietary options," Ornish says. "Because these men had prostate cancer, we put them on the more intensive regimen. But the more people change, the better the outcomes. It may not be necessary to make changes to this degree for people who do not have cancer to begin with."

Perhaps the most surprising thing about the study is not that the men changed their genetic profiles, but that they changed them so quickly.

"People say, 'Why bother about it? But when they see that in just three months these changes can make a difference, they may change their minds," Ornish says. "It is not really so much about risk-factor reduction or preventing something bad from happening. These changes can occur so quickly you don't have to wait years to see the benefits."

Ornish and colleagues report their findings in the June 17 issue of Proceedings of the National Academy of Sciences.

Show Sources


Ornish, D. Proceedings of the National Academy of Sciences, June 17, 2008; vol 105: pp 8369-8374.

Dean Ornish, MD, founder and president, Preventive Medicine Research Institute and clinical professor of medicine, University of California, San Francisco.

Christopher Haqq, MD, PhD, University of California, San Francisco.

Peter Carroll, MD, professor and chair of urology, University of California, San Francisco.

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