Can diet help fight prostate cancer?

Can adopting a healthier diet help fight prostate cancer? That's a question men newly diagnosed with prostate cancer often ask their doctors.

Several studies have shown that in countries where men eat a typical "Western" diet containing a large amount of meat, the incidence of prostate cancer, especially aggressive prostate cancer, is higher than in countries where plant-based foods are a primary part of the diet. Unfortunately, these studies weren't designed to prove cause and effect. So for now, definitive answers about prostate cancer and diet aren't yet in — although researchers are actively studying this topic.

Investigators launched a federally funded national study to see whether a diet that's higher in plant-based foods and lower in animal-based foods than the typical Western diet would help control tumor growth in men with early-stage prostate cancer.

The Men's Eating and Living (MEAL) study included men 50-80 years old who had small, low-grade tumors and who opted to have their condition followed closely (active surveillance) rather than undergoing immediate treatment. The researchers randomly assigned participants to telephone counseling about how to achieve the dietary MEAL goals or to a control group that received standard dietary advice for Americans.

The study participants in the MEAL group were instructed to eat nine servings of fruits and vegetables daily — significantly more than the three to four servings consumed each day by the typical American man — as well as two servings of whole grains and one serving of beans or other legumes. The participants in the control group received information regarding a standard healthy diet.

Here's what the MEAL eating plan looks like:

The initial results of the study showed that men with prostate cancer can sustain a healthier eating pattern. However there was no significant effect of the MEAL diet on two-year clinical progression among men on active surveillance for prostate cancer. Longer term benefits are still possible.

For more on new options for treating prostate cancer, and to learn about advances in the diagnosis and treatment of prostate cancer and other prostate conditions, buy the Annual Report on Prostate Diseases, a Special Health Report from Harvard Medical School.

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