Elevated Plasma Glucose and Lowered Triglyceride Levels From Omega-3 Fatty Acid Supplementation in Type II Diabetes

We studied the effect of omega-3 fatty acids (ω3FA) on glucose homeostasis and lipoprotein levels in eight type II (non-insulin-dependent) diabetic subjects ingesting 8 g/day to3FA for 8 wk as marine-lipid concentrate capsules. After ω3FA supplementation, fasting plasma glucose levels increased 22% (P = .005) and meal-stimulated glucose increased 35% (P = .036). The percentage of glucose elevation correlated with percentage ideal body weight (r = .73, P = .04). No significant changes were seen in fasting or meal-stimulated plasma insulin, glucose disposal, or insulin-to-glucagon ratios. Very-low-density lipoprotein cholesterol and triglyceride (TG) levels showed consistent reductions of 56% (P < .001) and 42% (P < .001), respectively, after ω3FA supplementation. Total cholesterol levels decreased 7% (P < .05) without alteration in low- or high-density lipoprotein cholesterol. Thus, ω3FA supplementation at a dose of 8 g/day significantly improves plasma TG levels but increases fasting and meal-stimulated glucose concentrations in the type II diabetic patient not treated with insulin or sulfonylurea agents. Marine-lipid concentrate capsules supplying large amounts of ω3FAs should be used cautiously in the type II diabetic patient.