A new scoring system rates each of the lifestyle habits linked with a lower risk for prostate cancer—and not just any prostate cancer but the aggressive kind that is most likely to kill a man. Each of the habits below helps reduce risk. Can you guess the most protective one?

A. Eating fatty fish once a week

B. Eating seven servings of tomatoes a week

C. Exercising vigorously for at least three hours a week

D. Eating little or no processed meats

E. Not smoking

F. Keeping weight under control

The correct answer is C—exercising vigorously for at least three hours a week.

But there’s a catch: All of the choices are preventive. They work together. Combine them, and you greatly increase your chances of getting through life without getting the most lethal kind of prostate cancer. Read on to find out how.


Most cases of prostate cancer are “indolent,” meaning that they are not likely to invade other organs. You could have this kind of cancer for years, even decades, and it wouldn’t threaten your life. But a significant percentage of cases of prostate cancer (10% to 15%) are of a very different kind—highly aggressive and prone to metastasize to other organs and the bones. This aggressive type of prostate cancer is often lethal.

It’s this deadly form of prostate cancer that you really want to prevent. Fortunately, a healthy lifestyle can be very effective at making sure you never get it. Various studies have found that a number of dietary factors are preventive—eating tomatoes (rich in the protective phytochemical lycopene)…fatty fish (for omega-3 fatty acids)…not eating processed meat such as bacon (high in carcinogenic nitrates). Vigorous exercise (we’ll let you know exactly what that means below), not smoking and avoiding obesity have also shown up in the research as protective.

To find out which is the most protective, researchers at the University of California, San Francisco, developed a scoring system based on two databases that followed large numbers of men in midlife and older for more than 20 years.

Exercise won by a mile.


For men over age 60, a habit of regular intense exercise—enough to get you to break a sweat—for a minimum of three hours a week was linked with a huge reduction in lethal prostate cancer risk of 36%, compared with risk in men who exercised less often or not at all.

If you’re exercising to the point of sweating less frequently than that, you may want to up your game. Men who exercised less often were no more protected than men who didn’t get any exercise. But you don’t have to become an Ironman triathlete. There’s no requirement that you sweat for the entire hour. Just do something that gets your heart rate up so that your skin shines. Says study author Stacey A. Kenfield, ScD, assistant professor in the Department of Urology, University of California, San Francisco, “As long as the man is sweating, it counts.”

How does vigorous exercise in particular protect the prostate? Researchers aren’t sure, but it may be related to changes in hormones, immunity, antioxidant defenses and insulin levels. High-intensity exercise is particularly effective at lowering blood insulin levels, and high insulin levels can promote tumor growth.


While vigorous exercise had the greatest effect, dietary and other factors were also protective…

  • Eating fatty fish (such as salmon) at least once a week: 17% reduced risk.
  • Eating seven or more servings of tomatoes per week: 18% reduced risk.
  • Eating fewer than three servings a week of processed meat: 22% reduced risk.
  • Having a body mass index of 30 or less (that is, being normal weight or overweight but not obese): 7% reduced risk.
  • Not smoking: 12% reduced risk.

The big benefits happen when you put these healthy lifestyle habits together. Men who had all three healthy dietary habits, compared with men with zero such habits, for example, were 46% less likely to get lethal prostate cancer, according to the largest of the two databases.

Men who could check off at least five of the six healthy habits, compared with men with only one healthy habit or none, had a 68% lower risk of developing lethal prostate cancer. Since prostate cancer is more common as men age, the researchers separately calculated the preventive benefit for men over 60 in the US. “We estimated that 47% of lethal prostate cancer cases could be prevented in the United States if men over 60 had five or more of these healthy habits,” says Dr. Kenfield.

On top of that, it’s even possible that a healthy lifestyle is more powerful than this scoring system finds. According to the study authors, many other dietary factors—eating foods rich in “good fats” such as avocados, nuts and olives, eating cabbage-family vegetables such as broccoli, consuming less dairy and not taking single supplements unless your doctor prescribes them—can also reduce prostate cancer risk.

What if you already have prostate cancer? All of these healthy habits are associated with increasing your chances of beating the cancer, too.