Zinc May Increase Prostate Cancer Risk

BETHESDA, Md.--Men with supplemental zinc intake greater than 100 mg/d were shown to be at an increased risk of prostate cancer compared to non-users, according to a study published in the July 2 issue of the Journal of the National Cancer Institute (95, 13:1004-7, 2003) (jncicancerspectrum.oupjournals.org). Research from the Division of Cancer Epidemiology and Genetics at the National Cancer Institute also indicated the risk was further increased when supplements were used for 10 years.

Researchers evaluated data from the 46,974 health professionals who were involved in the Health Professionals Follow-Up Study, and during 14 years of follow-up, identified 2,901 new cases of prostate cancer. Of these, 434 were diagnosed as advanced cancer. Supplemental zinc intake at doses up to 100 mg/d was not associated with prostate cancer risk, although those taking more than 100 mg/d had twice the risk of non-users for developing the disease. Researchers concluded that while they could not rule out confounding by supplemental calcium intake or unmeasured zinc supplement use, chronic zinc over-supply may have a hand in causing prostate cancer. The researchers added that additional investigation is warranted to determine zinc's role in prostate cancer risk.