Antioxidants are not linked to decreased prostate Ca risk

Dietary or supplemental antioxidants do not appear to be associated with a decreased risk of prostate cancer among men in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, suggests a study published last month in the Journal of the National Cancer Institute (2006; 98:245-54). But the study did find vitamin E and beta-carotene supplements to be associated with reduced risk in male smokers and in men with low dietary beta-carotene intake, respectively.

Richard B. Hayes, PhD, and colleagues at the National Cancer Institute assessed the risk of prostate cancer among 29,361 men, ages 55 to 74 years, enrolled in the PLCO Cancer Screening Trial, based on their daily intake of beta-carotene, vitamin E, and vitamin C. Overall, dietary or supplementary intake of these antioxidants was not associated with prostate cancer incidence in this patient group.

However, for current or recent smokers, high-dose, long-duration vitamin E supplementation was associated with a reduced risk of advanced prostate cancer, and for men with a low dietary intake of beta-carotene, high-dose supplementation was linked with a reduced risk of prostate cancer.

“Our cohort findings, although based on relatively short follow-up, do not provide strong support for population-wide implementation of high-dose antioxidant supplementation for the prevention of prostate cancer,” the authors wrote. “They do suggest, however, that in certain population subgroups, there was an association between supplement intake and reduced risk of prostate cancer.”