Effect of Various Dietary Fatty Acid Ethyl Esters on Plasma Cholesterol and Lipoprotein Metabolism in Rats.

The present study was conducted to investigate the effect of specific fatty acid esters on lipid metabolism of rats fed diets containing highly purified fatty acid ethyl esters of palmitate, stearate, palmitoleate, oleate, linoleate, and alpha linolenate. The hypocholesterolemic and hypotriglyceridemic activity of palmitoleate was comparable with that of linoleate and alpha linolenate and was significantly greater than that of palmitate, stearate, and oleate. Plasma cholesterol and LDL-cholesterol were significantly higher in rats fed the palmitate diet than those fed the stearate one. Lecithin-cholesterol acyltransferase (LCAT) activity was higher in rats fed the palmitoleate, linoleate, and alpha linolenate than in rats fed the palmitate, stearate, and oleate. There was a highly negative correlation between LCAT activity and plasma cholesterol and free cholesterol levels. These results demonstrate that palmitoleate appears to be as effective as linoleate in lowering plasma cholesterol and triglyceride levels. The stearate does not strongly increase plasma cholesterol levels as much as palmitate.