Very long chain N-3 fatty acids intake and carotid atherosclerosis: an epidemiological study evaluated by ultrasonography.

Epidemiological studies have shown an inverse relationship between intake of N-3 fatty acids and incidence of stroke. And, there is a high incidence of stroke in patients with carotid atherosclerosis. We investigated the relationship between intake of N-3 fatty acids and carotid atherosclerosis in the cross-sectional study. A total of 1920 Japanese, aged over 40 years, received a population-based health examination in 1999. They underwent B-mode carotid ultrasonography to evaluate the carotid intimal-medial thickness (IMT). Eating patterns were evaluated by a 105 items food frequency questionnaire. A complete data set was available for 1902 subjects (785 men and 1117 women). The mean eicosapentaenoic acid (EPA) intake in men was 0.32+/-0.23 g/day and in women was 0.31+/-0.20 g/day. The mean docosahexaenoic acid (DHA) intake in men was 0.52+/-0.34 g/day and in women was 0.49+/-0.29 g/day. With multiple linear regression analysis, after adjustments for age, sex, and total energy intake, intakes of EPA (P < 0.05), DHA (P < 0.05), and docosapentaenoic acid (P < 0.05) were significantly and inversely related to IMT. These data indicate that dietary N-3 fatty acid, especially very long chain N-3 fatty acids, may protect against carotid atherosclerosis.