Provitamin A carotenoid intake and carotid artery plaques: the Atherosclerosis Risk in Communities Study

We examined the cross-sectional association between intake of carotenoids with provitamin A activity and carotid artery plaques in 12773 participants of the Atherosclerosis Risk in Communities Study aged 45-64 y. Usual diet was assessed with a 66-item food-frequency questionnaire. Plaques were examined by B-mode ultrasound of multiple carotid artery segments. In both women and men, those in the highest quintile of carotenoid consumption had a lower prevalence of plaques (women, 25.4%; men, 36.0%) than those in the lowest quintile of carotenoid consumption (women, 29.3%; men, 39.8%). The prevalence odds ratios contrasting extreme intake quintiles were 0.82 (95% CI: 0.70, 0.97) in women and 0.85 (95% CI: 0.72, 1.01) in men. The associations diminished slightly after potential confounders were adjusted for. In women, the inverse association was particularly strong for current smokers (adjusted odds ratio contrasting extreme quintiles: 0.67; 95% CI: 0.45, 0.98). In men, no such effect modification by smoking was seen. The inverse association was somewhat stronger in men aged 55-64 y than in those aged 45-54 y, whereas age made little difference in women. These findings, together with previous findings that carotenoid intake was unrelated to average carotid artery wall thickness, suggest that carotenoids may exert their influence later rather than earlier in the atherosclerotic process, and support the hypothesis that carotenoids or other plant-derived compounds may play a role in preventing arterial plaque formation.