Vitamin E, C Don’t Affect Cardio Disease

Neither vitamin E nor vitamin C supplements reduced the risk of major cardiovascular events, according to a large, long-term study of male physicians in the Nov. 12 issue of JAMA (2008;300(18):2123-2133). The article is being released early online Nov. 9 to coincide with the scientific presentation of the study findings at the American Heart Association (AHA) meeting.
Most adults in the United States have taken vitamin supplements in the past year, according to background information provided by the authors. “Basic research studies suggest vitamin E, C and other antioxidants reduce cardiovascular disease by trapping organic free radicals, by deactivating excited oxygen molecules, or both, to prevent tissue damage.” Some previous observational studies have supported a role for vitamin E in cardiovascular disease prevention. Some previous observational studies have also shown a role for vitamin C in reducing coronary heart disease risk.
In this study, known as the Physicians’ Health Study II, Howard D. Sesso, Sc.D, M.P.H., and colleagues from Brigham and Women’s Hospital, Harvard Medical School and School of Public Health and VA Boston Healthcare System, Boston, assessed the effects of vitamin E and vitamin C supplements on the risk of major cardiovascular disease events among 14,641 male physicians. These physicians were 50 years or older and at low risk of cardiovascular disease at the beginning of the study in 1997, and 754 (5.1 percent) had prevalent cardiovascular disease. The study participants were randomized to receive 400 IU of vitamin E every other day or a placebo and 500 mg of vitamin C daily or a placebo.
“During a mean (average) follow-up of eight years, there were 1,245 confirmed major cardiovascular events,” the researchers reported. There were 511 total myocardial infarctions (heart attacks), 464 total strokes and 509 cardiovascular deaths, with some men experiencing multiple events. A total of 1,661 men died during follow-up. Compared with placebo, neither vitamin E nor vitamin C had an effect on the prevention of major cardiovascular events. “Neither vitamin E nor vitamin C had a significant effect on total mortality, but vitamin E was associated with an increased risk of hemorrhagic stroke.”
In conclusion the authors wrote: “In this large, long-term trial of male physicians, neither vitamin E nor vitamin C supplementation reduced the risk of major cardiovascular events. These data provide no support for the use of these supplements for the prevention of cardiovascular disease in middle-aged and older men.”
Andrew Shao, Ph.D., vice president, scientific and regulatory affairs, CRN, commented: “We commend the researchers for undertaking this important prevention trial which sought to confirm positive results demonstrated by earlier observational trials on these antioxidant vitamins. 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.
From a consumer’s point of view, it can be frustrating to have more questions than answers, but for scientists, this can be intriguing. The truth is we don’t have conclusive scientific evidence in the form of randomized, controlled trials that demonstrate exactly how to prevent cardiovascular disease. We do know there are some well-known practical approaches—like not smoking, maintaining a healthy weight, consuming a diet with a variety of foods, regular exercise, seeing your physician, and responsible use of vitamin supplements.
Consumers should not take vitamins expecting that vitamins alone will prevent cardiovascular disease, but they should continue to take vitamins for the general health benefits they provide.”