Dietary and circulating antioxidant vitamins in relation to carotid plaques in middle-aged women.

Abstract

BACKGROUND The results of the few studies conducted on the relation between antioxidant vitamins and carotid atherosclerosis have been inconclusive. OBJECTIVE We evaluated the association between preclinical carotid atherosclerosis, as determined by high-resolution B-mode ultrasound, and both the intake amounts and plasma concentrations of antioxidant vitamins. DESIGN Among 5062 participants in Progetto Atena, a population-based study on the etiology of cardiovascular disease and cancer in women, 310 women were examined by B-mode ultrasound to detect early signs of carotid atherosclerosis. The participants answered a food-frequency questionnaire, and their plasma concentrations of vitamin E, vitamin A, and carotenoids were measured. None of the women took vitamin supplements. RESULTS The occurrence of atherosclerotic plaques at the carotid bifurcation was inversely associated with tertiles of vitamin E intake; the test for a linear trend across tertiles was significant (P < 0.05). Similarly, the ratio of plasma vitamin E to plasma cholesterol was inversely related to the presence of plaques at the carotid bifurcation; the test for a linear trend across tertiles was significant (P < 0.02). No association was found between the intake of other antioxidant vitamins (vitamins A and C and carotenoids) or their plasma concentrations and the presence of carotid plaques. CONCLUSIONS An inverse association was found between both the intake amount and plasma concentration of vitamin E and preclinical carotid atherosclerosis in middle-aged women. This association was independent of other cardiovascular risk factors, was not related to vitamin supplements, and supports the hypothesis that low vitamin E intake is a risk factor for early atherosclerosis.