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

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.