Effect of supplementation with dietary seal oil on selected cardiovascularrisk factors and hemostatic variables in healthy male subjects

The average daily consumption of seal oil by the Inuit people is approximat ely 8-9 g, yet there is very little information on the effect of seal oil c onsumption on cardiovascular disease risk factors. In this study, 19 health y, normocholesterolemic subjects consumed 20 g of encapsulated seal oil con taining eicosapentaenoic acid (EPA; 20,5n-3), docosahexaenoic acid (DHA; 22 :6n-3), and docosapentaenoic acid (DPA: 22:5n-3) or 20 g of vegetable: oil (control) per day for 42 days. Levels of selected cardiovascular and thromb otic risk factors as well as fatty acid profiles of serum phospholipid and nonesterified fatty acid (NEFA) were determined, EPA levels in serum phosph olipid and NEFA increased by 4.3- and 2.7-fold, respectively, in the seal o il supplemented group, DHA levels rose 1.5- and 2.1-fold, respectively, and DPA levels rose 0.5- and 0.7-fold, respectively. Arachidonic acid (AA) lev els dropped by 26% in both serum phospholipid and serum NEFA. There was a s ignificant decrease in the ratio of n-6 to n-3 fatty acids in serum phospho lipid from 7.2 to 2.1 and a significant increase in the ratio of EPA/AA in NEFA. Ingestion of seal oil raised the coagulant inhibitor, protein C, valu es by 7% and decreased plasma fibrinogen by 18%. No alterations in other he mostatic variables, including plasma activity of Factors VII, VIII, IX, and X and antithrombin, or in the concentrations of von Willebrand Factor, tot al cholesterol, high-density lipoprotein cholesterol, low-density lipoprote in cholesterol, triglyceride, glucose, Apo A-1, or lipoprotein(a) were obse rved in either group. Other risk factors for cardiovascular disease, includ ing hematocrit, white blood cell count, plasma viscosity, systolic and dias tolic blood pressures, heart rate, and platelet aggregation after stimulati on with ADP or collagen did not change. Our results indicate that seal oil supplementation in healthy, normocholesterolemic subjects decreased the n-6 /n-3 ratio and increased EPA, DHA, and DPA and the ratio of EPA/AA and DHA/ AA in the serum phospholipid and NEFA while exhibiting a modest beneficial effect on fibrinogen and protein C levels. (C) 1999 Elsevier Science Ltd. A ll rights reserved.