Antioxidants Not Associated With Increased Melanoma Risk

A recent randomized trial of antioxidants for cancer prevention found that daily supplementation with nutritionally appropriate doses of vitamins C and E, beta carotene, selenium and zinc appeared to increase the risk of melanoma in women four-fold, according to background information in the article. Because an estimated 48 percent to 55 percent of U.S. adults use vitamin or mineral supplements regularly, the potential harmful effects of these nutrients is alarming, the authors note.

Maryam M. Asgari, M.D., M.P.H., of Kaiser Permanente Northern California, Oakland, and colleagues examined the association between antioxidants and melanoma among 69,671 women and men who were participating in the Vitamins and Lifestyle (VITAL) study, designed to examine supplement use and cancer risk. At the beginning of the study, between 2000 and 2002, participants completed a 24-page questionnaire about lifestyle factors, health history, diet, supplement use and other cancer risk factors.

Intake of multivitamins and supplements during the previous 10 years, including selenium and beta carotene, was not associated with melanoma risk in either women or men. The researchers also examined the risk of melanoma associated with long-term use of supplemental beta carotene and selenium at doses comparable to the previous study and found no association.

"Consistent with the present results, case-control studies examining serologic [blood] levels of beta carotene, vitamin E and selenium did not find any association with subsequent risk of melanoma," the authors write. "Moreover, the Nurses' Health Study reported no association between intake of vitamins A, C and E and melanoma risk in 162,000 women during more than 1.6 million person-years of follow-up."

This study was supported in part by a grant from the National Institute of Arthritis Musculoskeletal and Skin Diseases and by grants from the National Cancer Institute.