Dietary antioxidants such as vitamin E, vitamin C, beta carotene and flavonoids may retard atherosclerosis by preventing low density lipoprotein oxidation. Observational epidemiological studies, including ecological correlations, case control and prospective studies, indicate that high vitamin E levels may be associated with decreased cardiovascular disease. Beta carotene may be protective among smokers and the elderly. Few studies have been able to show that vitamin C has a protective effect. A handful of intervention studies have examined the effects of vitamin E and beta carotene with mixed results. While few side effects of antioxidant supplementation are known, the results of current, large-scale studies in primary intervention must be awaited before recommendations can be made. Increased intake of fruits and vegetables that are rich in antioxidants is recommended.