12.01.08
Results from the Physicians’ Health Study-II, a large, long-term trial of male physicians, indicate neither vitamin E nor vitamin C supplementation reduce the risk of major cardiovascular events. Findings from the randomized, double-blind, placebo-controlled factorial trial were recently published in the Journal of the American Medical Association (JAMA). For this study, which began in 1997 and was completed in 2007, 14,641 U.S. male physicians initially aged 50 years or older were enrolled, including 754 men (5%) with prevalent cardiovascular disease (CVD) at randomization. Participants received individual supplements of 400 IU of vitamin E every other day and 500 mg of vitamin C daily. During a mean follow-up of eight years, there were 1245 confirmed major cardiovascular events. Compared with placebo, researchers claim neither vitamin E nor vitamin C had any effect on incidence of these events.
Andrew Shao, PhD, vice president, scientific and regulatory affairs, with the Washington, D.C.-based Council for Responsible Nutrition (CRN), responded to the study, saying, “We commend the researchers for undertaking this important prevention trial. Although the results did not demonstrate an overall benefit, the results also do not discount the earlier epidemiological data showing that people with high intakes of vitamins E and C may have a lower risk of cardiovascular disease. Nutrition research is extremely complex, and doesn’t always provide clear-cut answers. This study raises an interesting set of scientific challenges as to why the benefits found in observational studies have not been confirmed in this kind of trial.”
Andrew Shao, PhD, vice president, scientific and regulatory affairs, with the Washington, D.C.-based Council for Responsible Nutrition (CRN), responded to the study, saying, “We commend the researchers for undertaking this important prevention trial. Although the results did not demonstrate an overall benefit, the results also do not discount the earlier epidemiological data showing that people with high intakes of vitamins E and C may have a lower risk of cardiovascular disease. Nutrition research is extremely complex, and doesn’t always provide clear-cut answers. This study raises an interesting set of scientific challenges as to why the benefits found in observational studies have not been confirmed in this kind of trial.”