Researchers have yet to make a definite link between diet and prostate cancer, but some sensible steps may lower men's risk and help protect against other diseases and health conditions at the same time.

About one in five American men develop prostate cancer. Prostate cancer is slow-growing, and a relatively small proportion of men who develop it actually die from it. Even so, prostate cancer is the second-leading cause of cancer death in men, according to the Centers for Disease Control and Prevention.

Right now, there's no clear-cut way to prevent it.

Older men, African-Americans and men with a genetic predisposition to prostate cancer are at higher risk. Of course, those are risk factors individuals can do little to control.

But researchers also believe diet and lifestyle may help prevent prostate cancer. If it's true, it's good news, because what you eat and whether or not you exercise are within your control.

Research points to some reasonable starting points:

• Eat a diet rich in plant matter. Eat heaping helpings of fresh fruits, vegetables, beans and peas and plenty of whole grain breads, cereals, seeds and nuts. Limit sweets, refined flour, added sugar, salt, trans fat, animal fats and meat. People who eat this way have lower rates of several cancers, coronary artery disease, obesity, high blood pressure and diabetes.
• Moderate your calorie intake. Add more low-calorie foods to your diet -- especially fruits and vegetables -- and eat fewer high-calorie desserts and snacks. No direct link between obesity and prostate cancer risk has been determined, but weight may affect cancer risk by influencing hormone levels.
• Be physically active. Strive for vigorous physical activity most days of the week. You'll lower your risk for several chronic diseases and more easily maintain an ideal weight.

What else can you do?

Several theories involve individual nutrients and foods touted by some as providing special protection against prostate cancer. A few show promise, but none are proven effective:

• Vitamin E and selenium supplements. Scientists have studied their antioxidant effects and other actions, but results have been mixed. Save your money and get your nutrition from whole foods containing nutrients packaged as intended by Mother Nature. If you do take supplements, let your health-care provider know. Supplements can have unintended side effects and may interfere with medications.
• Omega-3 fatty acids and vitamin D. They're found in oily fish such as salmon, mackerel, herring and sardines. Omega-3 fatty acids have been found in some studies to reduce the risk of some forms of cancer, and low blood levels of vitamin D have been linked with higher rates of prostate cancer. There isn't enough evidence in either case, though, to warrant taking supplements to prevent prostate cancer. Fish eaters should eat no more than two average servings or 12 ounces of fish per week to balance the nutritional benefits with risks from contamination, according to the Food and Drug Administration and Environmental Protection Agency.
• Lycopene. One study linked high intakes of tomatoes, which are rich in the antioxidant lycopene, with lower risk of prostate cancer. The link is weak, though, according to a recent review of the research. Eat all the tomatoes you want, but don't bother with lycopene supplements.

Pomegranate juice and acai, a fruit from a type of palm tree, are in vogue now, too, as cure-alls that help protect against various forms of cancer. While they won't hurt you, they hold no advantages that you can't get from many other colorful fruits.

It seems for now, what's best for men is what's best for all of us.

Suzanne Havala Hobbs is a licensed, registered dietitian and author. She holds a doctorate in health policy and administration from UNC-Chapel Hill, where she is a clinical assistant professor in the School of Public Health. Send questions and comments to suzanne@onthetable.net.