The case-control study used data collected in ARIC to test the hypothesis that individuals in the lowest quintile of vitamin C, vitamin E and carotenoid consumption were at higher risk of asymptomatic atherosclerosis than those consuming greater amounts. Antioxidant intake was assessed by a validated food frequency questionnaire and a diet supplement survey. Cases were those with asymptomatic carotid artery atherosclerosis as determined by B-mode ultrasonography. Controls were those without evidence of carotid artery atherosclerosis. Secondary analyses determined which sex-race subgroups were at particular risk due to low antioxidant consumption.