To study the effects of dietary
trilinoelaidate (tt18:2) on metabolic parameters, as they relate to essential
fatty acid metabolism, a diet containing "adequate"
linoleic acid with incremental isocaloric ttl8:2 supplementation was formulated. This diet was fed to rats for 11 weeks and
oxygen (O2) consumption, insensible water loss (IWL), growth parameters and
liver fatty acid composition evaluated at specified time intervals. The results showed that while an essential
fatty acid deficient diet (hydrogenated
tallow) increased IWL and decreased
body weight gains, O2 consumption remained unaltered. Dietary tt18:2, while accumulating in liver
lipids, apparently inhibiting
delta 6 desaturase, as evidenced by 18.2/20.4 ratios, did not alter O2 consumption of IWL. At the highest level of tt18:2 fed (2.5 weight percent of
dietary fat) there was a noticeable decrease in
body weight gains by the 11th week; organ weights, however, were not affected. While the increased consumption of dietary
trans fatty acids has raised questions regarding their potential biologically detrimental effects, the present study indicated that gross metabolic alterations related to classical essential
fatty acid deficiency symptoms are not precipitated in the rat by tt18:2 levels comparable to those consumed in a normal human diet.