Decreased Platelet Activity Without Change in Fibrinolytic Activity After Low Dosages of Fish Oil

Abstract

The effects of low-dose (350 mg daily) polyunsaturated fatty acids from fish oil, either in gelatine capsules or microencapsulated, were investigated in a non-blind, randomized, crossover study of 12 healthy male volunteers. The authors measured the incorporation of eicosapentaenoic acid (EPA) into platelets membranes, platelet aggregability by adenosine diphosphate (ADP) and adrenaline, and fibrinolytic activity as euglobulin lysis time, after two and six weeks of therapy. Both formulations resulted in increased incorporation of EPA into platelet membranes, and the microencapsulated formulation also significantly increased the platelet level of ADP for irreversible aggregation (by about 60%). Fish oil in gelatine capsules had a smaller, non-significant effect in the same direction. Both formulations reduced adrenaline-induced aggregability, but the effects did not attain significance. Neither formulation altered fibrinolysis. The data show that low doses of fish oil in microencapsulated form significantly lower platelet aggregability, without affecting fibrinolysis.