Consumption of omega-3 fatty acids is not associated with a reduction in carotid atherosclerosis: the Genetics of Coronary Artery Disease in Alaska Natives study.

OBJECTIVE: This study was designed to evaluate the relation between omega-3 fatty acid (FA) consumption and atherosclerosis.
BACKGROUND: The hypothesis that omega-3 FAs protect against atherosclerosis has not been tested with objective measures of atherosclerosis.
METHODS: A population-based sample of 1131 Alaskan Eskimos of age >or=18 underwent ultrasound assessment of carotid atherosclerosis. Those of age >35 (N=686) were included in the analysis. Diet was assessed by a food frequency questionnaire. Intimal-medial thickness (IMT) of the far wall of the distal common carotid arteries and plaque score (number of segments containing plaque) were assessed.
RESULTS: Mean consumption of total omega-3 FAs was 4.76 g/day in those without and 5.07 g/day in those with plaque. In models adjusting for relevant risk factors, presence and extent of plaque were unrelated to intake of C20-22 omega-3 FAs or total omega-3 FAs. In contrast, the odds of plaque rose significantly with quartiles of palmitic (p=0.02) and stearic acid intake (p=0.04). The extent of plaque (or plaque score) was also associated with a higher percentage intake of palmitic acid (p=0.01). IMT was negatively associated with grams of C20-22 omega-3 FAs (p=0.05), total omega-3 (p=0.05), palmitate (p=0.03), and stearate (p=0.03) consumed.
CONCLUSIONS: Dietary intake of omega-3 FAs in a moderate-to-high range does not appear to be associated with reduced plaque, but is negatively associated with IMT. The presence and extent of carotid atherosclerosis among Eskimos is higher with increasing consumption of saturated FAs.