According to two of the largest trials ever conducted on vitamins and cancer prevention men do not reduce their chances of prostrate cancer with antioxidant vitamins or supplements. Reported in the December 9 Early Release issue of the Journal of the American Medical Association, the study found that vitamin C, vitamin E and selenium don't help ward of prostrate cancer or any type of disease in men.

J. Michael Gaziano, MD, MPH, from the Brigham and Women's Hospital and Harvard Medical School in Boston, Massachusetts, and colleagues from the Physicians' Health Study II said, "Many individuals take vitamins in the hopes of preventing chronic diseases such as cancer, and vitamins E and C are among the most common individual supplements. A large-scale randomized trial suggested that vitamin E may reduce risk of prostate cancer; however, few trials have been powered to address this relationship. No previous trial in men at usual risk has examined vitamin C alone in the prevention of cancer."

In the Selenium and Vitamin E Cancer Prevention Trial, or SELECT, led by Scott M. Lippman, M. D., of the University of Texas M. D. Anderson Cancer Center, and Eric A. Klein, M. D., of the Cleveland Clinic Lerner College of Medicine researchers studied 35,533 men in there 50's who did not have cancer. They were given selenium and vitamin E alone or in combination and others a placebo. Several years later it was found that they had the same risk of developing the disease as had the men who were given a placebo.

The second study the Physicians' Health Study II Randomized Controlled Trial (of vitamins C and E), led by J. Michael Gaziano, M. D., of Brigham and Women's Hospital and VA Boston Healthcare System was conducted on 14,641 men and they were given a combination of vitamin E and vitamin C or a placebo. In this study also it was found that the vitamins did not reduce the risk of prostrate or any other type of cancer.

"In this large, long-term trial of male physicians, neither vitamin E nor C supplementation reduced the risk of prostate or total cancer," the study authors said. "These data provide no support for the use of these supplements for the prevention of cancer in middle-aged and older men."

"It looks like these particular antioxidants are not effective," says Howard Soule, Ph. D., chief scientific officer of the Prostate Cancer Foundation in Santa Monica, California, who was not involved in either study.

"It is reassuring that there was not a clear signal of harm for either agent," the study authors said. "Results of the multivitamin arm of the PHS [Physicians' Health Study] II will be forthcoming in several years." The National Institutes of Health and BASF Corporation supported this study. Study agents and packaging were provided by BASF Corporation, Wyeth Pharmaceuticals, and DSM Nutritional Products Inc.