Influence of unsaturated oils on intestinal absorption of cholesterol

Abstract

The influence of dietary fatty acid composition on intestinal cholesterol uptake, absorption and synthesis was examined in rats fed diets enriched with lard, sunflower or corn oil (28% w/w). When cholesterol uptake was measured from intestinal everted sacs and brush border vesicles, no significant difference was observed between saturated, polyunsaturated and control diets. The cholesterol absorption measured in vivo was significantly lower in the group fed on corn oil diet as compared to groups fed on control or lard diets. This result was assessed by the fact that hepatic cholesterol synthesis which is inversely related to cholesterol absorption was three-fold higher with corn oil diet than with control or lard diets. When lard and vegetable oil diets were adjusted for β-sitosterol content, cholesterol absorption was similar with the three fat enriched diets. These results show that cholesterol absorption is not influenced by the fatty acid composition of the diet because the low concentration of plant sterols found in vegetable oils is sufficient to decrease significantly in vivo cholesterol absorption.