Elaidic Acid and Oleic Acid Have Opposite Effects on Serum Glucose, Insulin and Immunoglobulin Levels and Eicosanoid Production in Streptozotocin-Induced Diabetic Rats

The present study was designed to evaluate the physiological effect of trans fatty acid in the diabetic condition. After feeding the mixture of oleic (cis) or elaidic (trans) acids with safflower oil (3: 7, wt/wt) at the dietary level of 10% for 2 weeks, rats were treated with streptozotocin and reared on the same diets for an additional week. The dietary level of elaidic acid was 6.4 energy %, which corresponded to the level that causes an increase in plasma low-density lipoprotein cholesterol and a decrease in high-density lipoprotein cholesterol in humans. The following differences were observed in rats fed trans acid in comparison with those fed cis acid; (a) significant reduction of water consumption and serum glucose, and an elevation of serum insulin, (b) a reducing trend of serum and liver lipids, (c) a reducing trend of the proportion of stearic and arachidonic acids in liver phospholipids and (d) a significant reduction of the concentration of serum immunoglobulin G (IgG) and an increase in IgE. Thus, the results indicate that elaidic acid may not further aggravate metabolic disorders caused under the diabetic condition more than the cis counterpart even when consumed at a relatively high level, with the exception of the response of serum immunoglobulins.