Key Findings
The overall physiological significance of dietary ALA is controversial and often mixed results are reported. In this review, the problems with many of the previously conducted studies that have shown negative or no beneficial effects of ALA are described. These include differences in ALA feeding levels in different study populations and blunting effects of concomitant consumption of omega 6 and long-chain omega 3 fatty acids. The authors stress the need for more and better designed trials for ALA. This study supports a role for ALA (and DHA) on improving endothelial function by reducing inflammation, lowering blood lipids and reducing levels of the pro-inflammatory compound sVCAM-1 (soluble vascular cell adhesion molecule-1). In this study, the presence of carotid atherosclerosis were significantly and negatively correlated with ALA and DHA levels in erythrocyte membrane in a middle-aged and older Chinese population with a low intake of n-3 fatty acids.
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 alpha-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.
This is a free article, click below to view:
Link to Full Text