Effects of Omega-3 Polyunsaturated Fatty Acids on Platelet Function in Healthy Subjects and Subjects with Cardiovascular Disease

Hyperactivation and aggregation of platelets play a major role in thrombosis and hemostasis. The aims of this study were to investigate the effects of omega-3 polyunsaturated fatty acids (PUFAs) on platelet function. Light transmission aggregometry and flow cytometric analyses of platelet activation and platelet-leukocyte aggregates were determined at baseline and after 4 weeks of omega-3 (docosahexaenoic acid 520 mg and eicosapentaenoic acid 120 mg) supplementation. In total, 40 healthy subjects and 16 patients with a history of cardiovascular disease (CVD) completed the study. In healthy subjects, omega-3 PUFA significantly reduced adenosine diphosphate (ADP)-induced (maximum amplitude, 77.0% +/- 3.2% vs. 71.6% +/- 3.4%, p = 0.036; maximum slope, 86.3 +/- 1.8 vs. 80.7 +/- 2.1, p = 0.014) and adrenaline-induced platelet aggregation (maximum slope, 42.8 +/- 2.7 vs. 37.4 +/- 3.0, p = 0.013; lag time, 00:21 +/- 00:02 vs. 00:31 +/- 00:03 s, p = 0.002). Omega-3 PUFA also reduced P-selectin expression (40.5% +/- 2.9% vs. 34.4% +/- 2.4%, p = 0.049) on platelets and platelet-monocyte aggregates (38.5% +/- 2.6% vs. 31.4% +/- 2.5%, p = 0.022) after activation with ADP 0.5 mu M. There were fewer changes in platelet aggregation and activation found in subjects with CVD. Nevertheless, there was a reduction in the slope of arachidonic acid-induced platelet aggregation (13.21 +/- 6.41 vs. 4.88 +/- 3.01, p = 0.009) and increased lag time for U46619 (00:16 +/- 00:00 vs. 00:29 +/- 00:07 s, p = 0.018) induced platelet aggregation. Thus, 4-week supplementation of 640 mg omega-3 PUFA reduced measures of platelet aggregation and activation in healthy subjects but effects were less evident in patients with existing CVD. Our findings support the recommendation that the omega-3 PUFA dose be higher in CVD than among healthy subjects.