The comparative effects of n-3 and n-6 polyunsaturated fatty acids on plasma fibrinogen levels: a controlled clinical trial in hypertriglyceridemic subjects.

It has previously been shown that fish oil supplementation, compared to olive oil, reduces plasma fibrinogen. Presented here are the results of a randomized, double-blind, crossover controlled trail that compared the effects of dietary n-3 and n-6 fatty acid supplementation on plasma fibrinogen levels in 10 patients with hyperlipoproteinemia types IIb or IV. Plasma fibrinogen levels showed statistically significant reductions during both the fish oil and corn oil treatment periods. Other variables related to hemostasis which showed no significant changes from baseline included tissue plasminogen activator activity and inhibitor, protein C antigen, antithrombin III activity, bleeding time, and platelet counts. These data confirm the two previous reports that fish oil supplementation is associated with reductions in plasma fibrinogen levels, thereby modifying a potential nonlipid risk factor for cardiovascular disease. Unlike previous reports, however, n-6 polyunsaturated fatty acids were also associated with significant reductions in fibrinogen levels. Therefore, it is premature to conclude that the fibrinogen-lowering effects of dietary fish oil are unique to n-3 polyunsaturated fatty acids.