The effects of fish oil versus corn oil on subjects with hyperlipidemia and type II, noninsulin dependent diabetes mellitus

Abstract

Twenty-five subjects (10 males, 15 females, mean age = 54±7.55years) with type II, noninsulin dependent diabetes mellitus and essential hyperlipidemia were randomly assigned to one of four treatment groups: 9 gm fish oil/day, 18 gm fish oil/day, 9 gm corn oil/day, or 18 gm corn oi l/day capsule supplementation for twelve weeks. The level of oil supplementation (9gm/day compared with 18gm/day) did not have significant effect within each oil group. Significant (p<0.05) differences were found when the type of oil, fish oil versus corn oil were compared. Significantly lowered plasma very low density lipoprotein (VLDL)-cholesterol (p<0.007), plasma triglycerides (TG) (p<0.015), and plasma VLDL-TG (p<0.02) were found in subjects consuming fish oil supplements than in those consuming corn oil. In addition, total plasma TG was decreased by 22 percent (p<0.05) during the course of supplementation in the fish oil group. Plasma low density lipoprotein (LDL)-cholesterol was significantly (p<0.003) higher in the fish oil group than in the corn oil group during supplementation. No significant differences were found in total plasma cholesterol, high density lipoprotein-cholesterol, fasting blood glucose, glycosylated hemoglobin Ale, body mass indices, blood pressure, total caloric intake, percentage of calories consumed from protein, carbohydrates, or fats, and dietary cholesterol intake between the groups of subjects consuming different oil capsules. The fish oil treatment groups had significantly (p < 0.05) higher dietary intakes of linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid and significantly (p<0.05) lower linoleic acid during capsule supplementation than did the corn oil groups. Subjects receiving 18gm/day of either fish or corn oil had a significantly (p < 0.05) higher unsaturated/saturated fat intake ratio during the capsule supplementation phase than did those receiving the 9 gm/day of either corn oil or fish oil. In the present study, omega-3 fatty acid supplementation improved plasma VLDL-cholesterol, VLDL-TG, and total TG while LDL-cholesterol deteriorated in subjects with type II diabetes. Omega-3 fatty acid supplementation did not pose any significant effects on glycemic control of study subjects.