Relation between dietary linolenic acid and coronary artery disease in theNational Heart, Lung, and Blood Institute family heart study

Background: Epidemiologic studies suggest that a higher consumption of eico sapentaenoic acid and docosahexaenoic acid is associated with a reduced ris k of cardiovascular disease. Studies in humans and animals also reported an inverse association between alpha -linolenic acid and cardiovascular disea se morbidity and mortality. Objective: We examined the relation between dietary linolenic acid and prev alent coronary artery disease (CAD). Design: We studied 4584 participants with a mean ( SD) age of 52.1 +/- 13.7 y in the National Heart, Lung, and Blood Institute Family Heart Study in a cross-sectional design. Participants' diets were assessed with a semiquant itative food-frequency questionnaire. For each sex, we created age- and ene rgy-adjusted quintiles of linolenic acid, and we used logistic regression t o estimate prevalent odds ratios for CAD. Results: From the lowest to the highest quintile of linolenic acid, the pre valence odds ratios of CAD were 1.0, 0.77, 0.61, 0.58, and 0.60 for the men (P for trend = 0.012) and 1.0, 0.57, 0.52, 0.30, and 0.42 for the women (P for trend = 0.014) after adjustment for age, linoleic acid, and anthropome tric, lifestyle, and metabolic factors. Linoleic acid was also inversely re lated to the prevalence odds ratios of CAD in the multivariate model (0.60 and 0.61 in the second and third tertiles, respectively) after adjustment f or linolenic acid. The combined effect of linoleic and linolenic acids was stronger than the individual effects of either fatty acid. Conclusions: A higher intake of either linolenic or linoleic acid was inver sely related to the prevalence odds ratio of CAD. The 2 fatty acids had syn ergistic effects on the prevalence odds ratio of CAD.