Evidence from epidemiologic studies, and from one unpublished study, suggests that greater intake of antioxidant vitamins is associated with reduced risk of coronary heart disease and stroke. Findings from an animal model indicate that increased intake of antioxidant vitamins prevents progression of aortic fatty streaks induced by an atherogenic diet, but not from more advanced injury-induced lesions. These observations suggest the hypothesis that increased antioxidant vitamin intake may prevent further progression of early atherosclerosis, possibly by means of reduced susceptibility of low density lipoprotein to oxidative modification and consequent cytotoxic, chemotactic, chemostatic, and unregulated uptake effects.