Effects of Moderate-Dose Omega-3 Fish Oil on Cardiovascular Risk Factors and Mood After Ischemic Stroke: A Randomized, Controlled Trial

Randomized, controlled, 1:1 trial conducted at a single hospital site in Auckland, New Zealand. The fish oil arm included clinically stable adults with CT-confirmed ischemic stroke more than 3 months earlier; 51 were randomized and 47 completed 12 weeks. Participants were generally older adults and predominantly overweight, with central adiposity.

Fish oil was given as 3 g/day of encapsulated hoki liver oil, providing about 1.2 g/day total omega-3 PUFA (DHA 0.7 g and EPA 0.3 g). Participants took 3 one-gram capsules each morning with food by mouth for 12 weeks; the comparator was placebo oil (palm plus soy oil).

Twelve weeks of moderate-dose fish oil did not improve cardiovascular or inflammatory biomarkers after ischemic stroke. Triglycerides were not different from placebo at week 12 (treatment difference -0.059 mmol/L, 95% CI -0.39 to 0.27; P = 0.72), and there were no meaningful effects on total cholesterol, HDL-C, LDL-C, LDL particle size, hsCRP, fibrinogen, or other lipid measures. Mood and health-related quality-of-life outcomes also did not improve overall; placebo showed greater improvement in GHQ-28 total score and social dysfunction (P = 0.04 and P = 0.03). The authors concluded that the dose or duration may have been insufficient and that oxidation of the fish oil may have reduced efficacy.

The trial was relatively small, single-center, and short at 12 weeks, which limits power and the ability to detect longer-term effects. The dose may have been insufficient for the targeted outcomes, and the authors raised concern that oxidation of the fish oils could have reduced efficacy. Generalizability is also limited to clinically stable, mostly older ischemic stroke survivors from one New Zealand site.