Vitamin E in the primary prevention of cardiovascular disease and cancer. The Women’s Health Study: A randomized controlled trial.

Observations from basic research and epidemiologic studies support the hypothesis that the antioxidant vitamin E may reduce the risks of developing cardiovascular disease (CV) and cancer, but findings from randomized trials challenge it.

The Women’s Health Study is the largest randomized clinical trial to investigate the impact of aspirin and vitamin E on the primary prevention of cardiovascular and cancer risk in women at least 45 years old. This paper reports the findings from the vitamin E component of the study.

The 39,876 women were randomly assigned to receive either 600 IU vitamin E (as all-natural -tocopherol) or a placebo every other day. Average follow-up was 10 years. Vitamin E did not significantly reduce the risk of major CV events, cancer, cancer mortality, or total mortality. However, among women aged >65 years there was a 24 percent significant reduction in CV mortality and a significant reduction in major CV events in the vitamin E group. Overall, this study with its large sample size and long duration does not support the use of vitamin E to prevent CV disease or cancer in women. Additional research is needed to determine whether the finding of a protective effect and a reduction in CV mortality with supplemental vitamin E in women aged >65 years can be confirmed.

Funding: National Heart, Lung and Blood Institute and National Cancer Institute, NIH and Natural Source Vitamin E Association.

I-M Lee, NR Cook, JM Gaziano, D Gordon, PM Ridker, JE Manson, CH Hennekens, and JE Buring. Journal of the American Medical Association (JAMA) 2005 294:56-65.