A recent examination of the dietary and supplement intake of men suggests that nutrients previously suggested as preventative for prostate cancer may actually have no effects. In this study, the researchers looked at dietary and supplement intakes of 9,559 men who participated in the Prostate Cancer Prevention Trial, which occurred in North America. Of these men, 1,703 of them were diagnosed with prostate cancer, mostly localized, after the start date.
Their findings revealed that neither the dietary intake nor the total intake (including supplements) of selenium; vitamins C, D & E; folate; lycopene; other carotenoids (excluding lycopene); zinc; or omega-3 fatty acids were associated with prostate cancer incidence. A small number of other nutrients, however, did appear to be associated with prostate cancer occurrence.
High calcium intake from both diet alone (>1,165mg/day) as well as from diet and supplements combined was associated with more than a 50% decreased risk of high-grade cancer compared to low calcium intake from diet alone (<598mg/day). Calcium intake of any level was not associated with risk of low-grade cancer.
Alcohol intake might also be associated to prostate cancer. Men in the group who consumed the most alcohol (14 or more drinks per week) had a 73% greater risk of having high-grade prostate cancer compared to men who consumed the least alcohol (less than 1 drink per week). There was no association between alcohol intake of any level and incidence of low-grade prostate cancers.
Perhaps the most notable finding was that men with higher intakes of polyunsaturated fat (over 8% of total calorie intake) were 2.4 times more likely to have high-grade prostate cancer compared to men with lower intakes (less than 5.4% of total calories). Although it is essential to get some polyunsaturated fats in our diet, having too many of the omega-6 fatty acids, the type of polyunsaturated fat predominant in the American diet, can lead to excess inflammation. Omega-6 fats are high in red meat and in vegetable oils such as corn, palm, soybean, or safflower. Since these oils are used largely in margarine and for frying, Omega 6 fats are abundantly found in commercial baked goods, snack foods and fast food.
With this new information, look with a skeptical eye at multivitamins or other supplements marketed as promoting prostate health. In fact, the Center for Science in the Public Interest sued a manufacturer for false claims that the selenium in its multivitamin helps prevent prostate cancer. Since filing this complaint with the Federal Trade Commission, the company has removed such claims.