Can New Diet Fight Prostate Cancer?

A new study reports that a diet of fruits, vegetables, whole grains and beans, coupled with exercise and meditation, can help slow, stop, or even reverse prostate cancer for men in the early stages of the disease.

Dr. Dean Ornish, a clinical professor of medicine at the University of California-San Francisco, led the study. Ornish, who is best known for his support of low-fat diets in reversing heart disease, is now contending that diet changes could also help reverse prostate cancer.

A group of men in Ornish's study underwent drastic diet and lifestyle changes, then saw reduced levels after three months of a blood marker for the disease. The marker, known as prostate specific antigens or PSA, is a protein produced by the prostate gland. High levels in a man's bloodstream can indicate prostate disorders, including non-cancerous enlargement of the prostate or prostate cancer.

Participating in Ornish's study required quite a change of menu for men who like high-fat foods like cheeseburgers and fries. The Ornish diet is extremely low-fat, with just 10 percent of the participants' nutritional intake coming from fat, according to the author of Eat More, Weigh Less, who presented his findings over the weekend at a conference on alternative therapies held at Harvard University.

"It is a vegan diet of fruits, vegetables, whole grains, beans, and soy products instead of dairy," Ornish told ABCNEWS' Good Morning America. "They exercised three hours a week and they did an hour of meditation or other stress-management techniques every day. They also took part in a weekly support group."

No Harm in Diet Changes

Since patients in the study had already opted to "watch and wait," rather than undergo standard treatments like surgery and radiation, there is no harm to Ornish's regimen, ABCNEWS' Dr. Tim Johnson said.

"In such a group, there's nothing to lose and possibly something to gain," Johnson said. "I say 'possibly' because it's too early to tell after just one year of follow-up. The key will be over whether longer follow-up there is a survival difference in the two groups," he said.

Still, Johnson warned that patients who need radiation or surgery should not interpret the study as a sign that they can simply diet and exercise their way to health, when that may not be the case.

"This is not a replacement for traditional therapy when that's indicated or a replacement for regular PSA screening to detect early prostate cancer," Johnson added.

Are Results Significant Enough?

Every year, nearly 200,000 American men are diagnosed with prostate cancer, and the disease kills 30,000 men annually. Those who survive face difficult treatment choices: either surgery or radiation, strategies that do not always work, and can cause impotence and incontinence.

Ornish's study looked at 84 men who were in the early stages of prostate cancer. None had elected to treat the disease with surgery or radiation. Half of them did not make any diet or lifestyle changes, while the other half adopted a low-fat diet and started moderate exercise.

At three months, researchers measured the subjects' PSAs, which will be measured again after one year. In just three months, the group with the low-fat diet and exercise changes saw their PSA's drop 6.5 percent, Ornish said. Those in the group who stuck closest to the diet and exercise regimen saw their PSA levels drop 9 percent.