Effects of dietary n-3 fatty acid-enriched chicken eggs on plasma and tissue cholesterol and fatty acid composition of rats.

The purpose of this study was to examine the effects of feeding n-3 polyunsaturated fatty acid (PUFA)-enriched chicken eggs on plasma and liver cholesterol levels and fatty acid composition in rats. Eggs were collected from laying hens fed diets containing 10% flax seed (Hn-3), 12% sunflower seed (Hn-6), or wheat and soybean meal control (CON). Yolk powders were prepared and fed at the 15% level to weanling female Sprague-Dawley rats for 28 days. Consumption of n-3 PUFA-enriched yolks significantly reduced both plasma and liver total cholesterol. Liver total lipids and phospholipids of rats fed Hn-3 diet were enriched with linolenic, eicosapentaenoic, and docosahexaenoic acids with a concomitant reduction of arachidonic acid in liver phospholipids. The plasma cholesterol of rats fed yolk powders enriched with n-6 PUFA (mainly linoleic acid) was reduced to the same extent as in those fed the n-3 enriched, but the liver cholesterol was significantly increased, indicating differential effects of dietary n-3 and n-6 PUFA. The results demonstrated that the cholesterolemic and tissue lipid modulating properties of chicken eggs could be modified in a favorable way by altering the fatty acid composition of yolk lipids through manipulation of laying hen diets.