A study from the National Cancer Institutes showed that taking more than 100 mg of zinc supplements a day doubles a man's chances of developing advanced prostate cancer (1). There are hundreds of products on the market today that contain zinc and they are advertised to help treat the prostate, help prevent prostate cancer, help treat an enlarged prostate, treat impotence, increase sexuality, increase ejaculation volume, and make a man more potent. All of these claims are unsupported by scientific data, and the study in the most prestigious cancer journal in the world, The Journal of the National Cancer Institute (July 2003), showed that men who take more than 100 mg a day of zinc double their risk for advanced prostate cancer. Men who took zinc supplements for 10 years or more also doubled their risk for prostate cancer.
In the United States, 10 percent of men who take zinc supplements take two to three times more than the recommended 11 mg of zinc per day. Not only have zinc supplements not been shown to help your prostate and sexuality, this study shows that excessive amounts of zinc may cause prostate cancer. Now we have to ask why there is a myth that zinc prevents prostate disease. The prostate contains the highest concentration of zinc of any tissue in the body. Semen contains the highest concentration of zinc of all body secretions. Because of this, many men take zinc supplements, even though there is no evidence that taking zinc can treat impotence, or prostate enlargement or cancer.
Sellers of zinc supplements base their recommendations to take zinc on studies from Egypt and Iran that show that boys who are deprived of zinc do not develop normal sexual characteristics. However, zinc deficiency is rare in North America, and no one has shown that taking more than the recommended amount of zinc increases sexuality. A recent analysis of supplements promoted for prostate health in Canada shows that most contain vitamins and other herbals that do not offer any proven benefit to the prostate (The Journal of Urology, July 2002). For example, there is little evidence that any vitamin treats prostate infections, impotence, prostate cancer, enlarged prostate or any other prostate malfunction. There is good data that lack of vitamin D may increase a man's chances of developing prostate cancer, so if you do not get plenty of sunshine or have dark skin, you may want to take a vitamin D supplement.
Prostate Supplements Not What They Claim to Be