Marine n-3 Polyunsaturated Fatty Acids and the Risk of Ischemic Stroke

Background and Purpose—

We hypothesized that total marine n-3 polyunsaturated fatty acids (PUFA), in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the diet and in adipose tissue (biomarkers of long-term intake and endogenous exposure) were inversely associated with the risk of ischemic stroke and its subtypes.

Methods—

The Diet, Cancer and Health cohort consisted of 57 053 participants aged 50 to 65 years at enrolment. All participants filled in a food frequency questionnaire and had an adipose tissue biopsy taken at baseline. Information on ischemic stroke during follow-up was obtained from The Danish National Patient Register, and all cases were validated. Cases and a random sample of 3203 subjects from the whole cohort had their fatty acid composition of adipose tissue determined by gas chromatography.

Results—

During 13.5 years of follow-up 1879 participants developed an ischemic stroke. Adipose tissue content of EPA was inversely associated with total ischemic stroke (hazard ratio [HR], 0.74; 95% CI, 0.62–0.88) when comparing the highest with the lowest quartile. Also, lower rates of large artery atherosclerosis were seen with higher intakes of total marine n-3 PUFA (HR, 0.69; 95% CI, 0.50–0.95), EPA (HR, 0.66; 95% CI, 0.48–0.91) and DHA (HR, 0.72; 95% CI, 0.53–0.99), and higher adipose tissue content of EPA (HR, 0.52; 95% CI, 0.36–0.76). Higher rates of cardioembolism were seen with higher intakes of total marine n-3 PUFA (HR, 2.50; 95% CI, 1.38–4.53) and DHA (HR, 2.12; 95% CI, 1.21–3.69) as well as with higher adipose tissue content of total marine n-3 PUFA (HR, 2.63; 95% CI, 1.33–5.19) and DHA (HR, 2.00; 95% CI, 1.04–3.84). The EPA content in adipose tissue was inversely associated with small-vessel occlusion (HR, 0.69; 95% CI, 0.55–0.88).

Conclusions—

EPA was associated with lower risks of most types of ischemic stroke, apart from cardioembolism, while inconsistent findings were observed for total marine n-3 PUFA and DHA.