INSULIN-RESISTANCE INFLUENCED BY DIETARY LINOLEIC-ACID AND TRANS-FATTY-ACIDS

The incidence of obesity, noninsulin-dependent diabetes mellitus (NIDD M), hypertension, and coronary artery disease has increased in the dev eloped world. At the same time, major changes in the type and amount o f fatty acid intake have occurred over the past 40-50 years, reflected in increases in saturated fat (from both animal sources and hydrogena ted vegetable sources), trans fatty acids, vegetable oils rich in lino leic acid, and an overall decrease in long chain polyunsaturated fatty acids (arachidonic acid, eicosapentaenoic acid, and docosahexaenoic a cid-C20-C22). Recent findings that C20-C22 in muscle membrane phosphol ipids are inversely related to insulin resistance, whereas linoleic ac id is positively related to insulin resistance, suggest that diet may influence the development of insulin resistance in obesity, insulin-de pendent diabetes mellitus (IDDM), hypertension, and coronary artery di sease (including asymptomatic atherosclerosis and microvascular angina ). These conditions are known to have genetic determinants and have a common abnormality in smooth muscle response and insulin resistance. I t is proposed that the current diet influences the expression of insul in resistance in those who are genetically predisposed. Therefore, cli nical investigations are needed to evaluate if lowering or preventing insulin resistance through diet by increasing arachidonic acid, eicosa pentaenoic acid, and docosahexaenoic acid, while lowering linoleic aci d and decreasing trans fatty acids from the diet, will modify or preve nt the development of these diseases.