The bleeding time effects of a single dose of aspirin in subjects receiving omega-3 fatty acid dietary supplementation.

Dietary supplementation with omega-3 fatty acids reduces platelet aggregation in subjects who usually eat a diet low in these fatty acids. Aspirin also has an antiplatelet effect. The clinical effects of the concomitant administration of these agents were examined in this double-blind controlled crossover trial. Twelve healthy adults were randomized to supplement their diet for 21 days with 8 g of omega-3 fatty acids or identical-looking olive oil capsules. At the end of each treatment period, bleeding times were obtained before and after the administration of one 325-mg aspirin tablet. Overall, percent change in bleeding time after omega-3 fatty acid supplementation was significantly prolonged compared with olive oil supplementation before aspirin administration but not after. Bleeding times were influenced significantly by the order of randomization in the two treatment groups. Changes in post-aspirin bleeding time varied in subjects after they received olive oil. Post-aspirin bleeding times after omega-3 fatty acid supplementation were prolonged compared with baseline values but not significantly prolonged when compared with those after olive oil administration. The authors concluded that the concomitant administration of a single dose of aspirin does not prolong bleeding time in subjects who eat a diet enriched by omega-3 fatty acids versus a diet enriched by olive oil.