Zinc may reduce prostate cancer mortality

High dietary intakes of zinc after diagnosis may be associated with lower prostate cancer-specific mortality for men, says a new Swedish study.

In the population-based cohort study, 525 men under 80 years of age were assessed to determine whether dietary zinc intake from the time of prostate cancer diagnosis onward can be associated with improved disease-specific survival (1). The study results showed that after an average of 7.6 years prostate cancer patients with the highest dietary zinc intakes (>15.6 mg/day) were up to 76% less likely die of prostate cancer compared to patients with the lowest intakes. Zinc seemed to contribute to improved survival rates only in men with early-stage cancers.

Zinc is an essential element with antioxidant properties that is involved in a range of cellular functions, including DNA repair. The concentration of zinc in prostate tissue is higher than that in any other tissue in the body; however, the influence of dietary zinc intake on these concentrations is unknown. Zinc concentrations in prostate tumors appear to be lower than those in adjacent normal tissue, because malignant cells lose the ability to accumulate zinc. An inverse association between zinc intake and prostate cancer has long been suspected; physiologic and experimental evidence supports the hypothesis, although the results of epidemiologic studies have been mixed.

Prostate cancer is the most commonly diagnosed cancer among men in many industrialized nations and is a leading cause of cancer death. The about 12-fold difference in international prostate cancer mortality rates between low-risk countries in Asia and high-risk countries such as Sweden suggests that environmental components, such as diet, may account for some of the observed variation.

1.  Epstein M. M. et al. Dietary zinc and prostate cancer survival in a Swedish cohort. Am J Clin Nutr. 2011: 93(3):586–593.