According to Dutch researchers at the Universiteit Maastricht, the antioxidant mineral selenium appears to have a protective effect against prostate cancer. Selenium is a trace mineral that pays important roles in detoxification and antioxidant defence mechanisms in the body. It is found most abundantly in Brazil nuts, while yeast, whole grains and seafood are also good dietary sources.

The association between prostate cancer and toenail selenium level was evaluated in 58,279 men, aged 55 to 69 years at entry into the Netherlands Cohort Study. In September 1986, the men completed a questionnaire on risk factors for cancer and provided toenail clippings for determination of baseline selenium status. The men were then followed up for incidence of prostate cancer.

The researchers found an inverse association between toenail selenium level and prostate cancer risk; therefore, the higher the selenium level, the lower the incidence of prostate cancer. The association was more pronounced in ex-smokers than in current smokers. The researchers conclude that “these results confirm the hypothesis that higher selenium intake may reduce prostate cancer risk” and that “future research on optimum dose level is needed.”

Cancer Epidemiology, Biomarkers and Prevention 2003:12;866–71