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.