Antioxidant vitamins and cardiovascular disease.

The hypothesis that antioxidant vitamins might reduce cardiovascular disease risk is based on a large body of both basic and human epidemiological research. One of the most consistent findings in dietary research is that those who consume higher amounts of fruits and vegetables have lower rates of heart disease and stroke as well as cancer. Recent attention has focused on the antioxidant content of fruits and vegetables as a possible explanation for the apparent protective effects. Basic research provides a plausible mechanism by which antioxidants might reduce the risk of atherosclerosis. A large number of descriptive, case-control, and cohort studies provide data suggesting that consumption of antioxidant vitamins is associated with reduced risks of cardiovascular disease. These data raise the question of a possible role of antioxidants, such as vitamins C and E and beta-carotene, in the primary prevention of cardiovascular disease, but they do not provide a definitive answer. Randomized trial data will be essential in fully assessing whether or not there is a causal effect of antioxidants in reducing the risk of cardiovascular disease. Results from several large-scale randomized trials of antioxidant supplements are now available, and additional trial data should be forthcoming in the near future, which will better define the role of antioxidants in the primary and secondary prevention of atherosclerotic disease. At this point, antioxidants represent a possible but as yet unproven means to reduce the risk of cardiovascular disease.