Dietary fatty acids in the management of diabetes mellitus

Dietary fatty acid recommendations for patients with diabetes mellitus may be neither similar to, nor extrapolated from, those for the normal population; some evidence suggests that diabetes prevalence may be correlated with the dietary ratio of n-6 to n-3 fatty acids. In human experiments, n-3 fatty acids may improve many of the metabolic sequelae of insulin resistance by lowering blood pressure and triacylglycerol concentrations. In animals, n-3 fatty acids may cause less weight gain than other fats; however, they may raise low-density-lipoprotein concentrations, increase hepatic glucose output, and decrease insulin secretion in non-insulin-dependent diabetes mellitus. In a minority of patients with insulin-dependent diabetes mellitus, glycemic control may be adversely affected n-6 Fatty acids lower plasma cholesterol but may increase lipoprotein oxidation. Glucose in the presence of transition metals may produce free radicals and result in pancreatic damage and the formation of glycosylation products that inhibit nitric oxide-mediated smooth muscle relaxation; fish oil may counter these effects. High-carbohydrate, low-fat diets, once recommended for diabetes mellitus, appear to aggravate hypertriglyceridemia and are inferior to diets high in monounsaturated fatty acids (MUFAs) if saturated fats are kept to a minimum. MUFA-rich diets improve lipid profiles and may also have antioxidant properties. However, high-fat diets-whatever their composition-promote obesity. Current advice individualizes carbohydrate and fat requirements to optimize blood glucose and lipid concentrations in a lifestyle program to control obesity, exercise, smoking, and blood pressure. Fatty acid modifications may fine-tune the diet if proper balance is kept between the different long-chain polyunsaturated fatty acids and antioxidant requirements.