TUESDAY, June 17 (HealthDay News) -- Genes may not fully control your destiny when it comes to cancer risk, according to a new study of men with prostate cancer.
New research suggests that stringent dietary changes, getting more exercise and practicing stress reduction can change the expression of hundreds of genes. Some of the changes positively affect genes that help fight cancer, while others help turn off genes that promote cancer development, according to the study, which is in this week's issue of the Proceedings of the National Academy of Sciences.
"These findings are very exciting. They counter the genetic nihilism I hear so often. People say, 'It's all in my genes, there's nothing I can do,' but actually you can do quite a lot," said the study's lead author, Dr. Dean Ornish, president of the Preventive Medicine Research Institute and a clinical professor of medicine at the University of California, San Francisco.
Previous epidemiological studies have found that the incidence of prostate cancer is significantly lower in areas of the world where people eat a more plant-based, low-fat diet instead of the higher-fat, higher-protein diet often consumed in the United States. Because of these findings, Ornish and his colleagues initially set out to see if altering diet and lifestyle could decrease the amount of prostate-specific antigen (PSA) in men who'd been diagnosed with early prostate cancer. PSA is a blood marker for prostate growth.
In September 2005, they reported that after intensive lifestyle changes -- consuming a vegan diet with about 10 percent of calories from fat, walking 30 minutes six times a week, and practicing stress management one hour daily -- men with early prostate cancer lowered their PSA scores by 4 percent, while men in the control group saw their PSA score rise by 6 percent.
But, the researchers didn't know what the mechanism behind the change was, according to Ornish. The current study was designed to elucidate the reasons behind the improvement.
