Erythrocyte membrane n-3 fatty acid levels and carotid atherosclerosis in Chinese men and women.

ABSTRACT

OBJECTIVE: Prospective studies have supported the beneficial effects of n-3 fatty acid consumption on cardiac deaths, but limited data focused on atherosclerosis. We investigated the associations between n-3 fatty acids in erythrocytes and atherosclerosis in middle-aged and older Chinese. METHODS: 847 subjects (285 men and 562 women), aged 40-65 years, from Guangzhou, China were included in this community-based cross-sectional study between December 2005 and January 2008. The levels of α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes were measured by gas chromatography. Carotid ultrasound examination was conducted to obtain intima-media thickness of the common carotid artery and the carotid bifurcation. Dietary data and other covariates were collected using interviewer-administered questionnaires. RESULTS: After adjustment for age, sex, and other confounders, negative dose-response associations between the contents of individual n-3 polyunsaturated fatty acids in the erythrocyte membrane and the prevalence of carotid artery wall thickening and plaque were observed. A comparison in the highest and lowest tertiles gave odds ratios (95% confidence interval) for thickening in the walls of the common carotid artery of 0.58 (0. 34-0.97; P-trend = 0. 037) for DHA, and 0.39 (0.23-0.67; P-trend < 0.001) for ALA. However, EPA was not significantly associated with carotid atherosclerosis. Similar results were found for thickening at the carotid bifurcation and the occurrence of carotid artery plaque. CONCLUSIONS: Higher levels of DHA and ALA in the erythrocyte membrane were significantly associated with a lower burden of subclinical atherosclerosis.