Supplements Ineffective in Preventing Prostate Cancer

Free Excerpt from JAMA Dec 9, 2008

Despite encouraging findings from earlier observational studies, vitamins E and C and selenium are ineffective in preventing prostate and other cancers in middle-aged and older men, according to two trials reported online in JAMA.

One trial randomized almost 15,000 middle-aged and older physicians to supplements of either vitamin E every other day, vitamin C daily, both, or placebo. By a mean follow-up of 8 years, there were no differences among the groups in the incidence of prostate or other site-specific cancers.

Similarly, a second trial followed prostate cancer risks in over 35,000 middle-aged and older men for a median of 5 years. They were randomized to either daily selenium, vitamin E, both, or placebo. As with the first trial, no significant differences in prostate cancer risks emerged among the groups.

An editorialist concludes that "physicians should not recommend selenium or vitamin E — or any other antioxidant supplements — to their patients for preventing prostate cancer."