An intensive diet and lifestyle program can slow – or possibly stop – the growth of early prostate cancer.

A new study shows that diet may play a significant role in stopping, or even reversing, early prostate cancer. Exercising more frequently, even in moderation, may also go a long way in retarding the disease.

The study findings apply only to men with early prostate cancer. This means that under a microscope the cancer cells do not appear aggressive. It also means that the prostate cancer had not spread outside the prostate.

No man should ever rely on lifestyle changes alone to treat prostate cancer without first talking to their doctor.

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Prostate cancer is the most common cancer in men in the U.S., according to the American Cancer Society. It is the second deadliest cancer in men, behind lung cancer. Most prostate cancers occur in men over 65.

Past research has indicated that men who eat high-fat diets may be more likely to develop prostate cancer.

“This study provides important new information for men with prostate cancer and all men who hope to prevent it,” says Peter Carroll, chairman of the department of urology at the University of California, San Francisco, in a news release.

Researchers studied 93 men whose biopsies had shown they had early prostate cancer. The participants were divided into two groups. All of them agreed to forgo any conventional prostate cancer treatment.

Prostate cancer is often a very slowly progressive cancer. Therefore, some men, particularly those with early prostate cancer, opt to delay treatment and wait and see how things go. This is called “watchful waiting.”

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The Program

The first group underwent intensive changes in diet and lifestyle including the following:

Vegan diet of predominantly fruits, vegetables, whole grains, legumes, and soy products. Soy supplements (one daily serving of tofu plus 58 grams of a fortified soy protein powdered beverage. Fish oil (3 grams daily), vitamin E (400 IU daily), selenium (200 micrograms daily), and vitamin C (2 grams daily). Moderate aerobic exercise (walking 30 minutes six days weekly). Stress management techniques (gentle yoga-based stretching, breathing, meditation, imagery, and progressive relaxation for 60 minutes daily). Participation in a one-hour support group once weekly to help stick to the program.

The diet is “intensive but palatable and practical,” according to the researchers. Previous studies have shown that most patients were able to stick to the diet for at least five years, they add. The program has already been shown to reverse progression of heart disease.

Three men in this group dropped out of the study because they said it was too difficult to follow.

The second group was asked to follow their doctors’ advice regarding lifestyle changes.

The researchers then followed PSA blood levels, a marker for prostate cancer progression. A rise in PSA indicates prostate cancer progression that may require treatment. Imaging studies were also done to look for any progression.

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No Treatment Required

After one year in the program, PSA levels decreased, on average, by 4% in the intensive diet group but increased by 6% in the second group.

None of the participants in the intensive diet group required treatment due to prostate cancer progression.

However, six men in the second group required conventional prostate cancer treatment – surgery, radiation, and/or hormone therapy – within the first year.

The researchers took it a step further and also tested how blood samples from the men affected prostate cancer cell growth in the lab.

Blood samples from the intensive diet group slowed prostate cancer cell growth by 70% in the lab but only by 9% in the second group.

“Changes in diet and lifestyle that we found in earlier research could reverse the progression of coronary heart disease may also affect the progression of prostate cancer,” says Dean Ornish, MD, clinical professor at the University of California, San Francisco, in a news release.

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By Patti Connor, Reviewed by Michael W. Smith, MD

SOURCES: Journal of Urology, September 2005. News release, University of California, San Francisco.