Effect of dietary lipids on beta-carotene absorption into micelles

Abstract

As beta-carotene is transported via micelles across the intestinal lumen for absorption, the factors that regulate uptake into micelles could also regulate at least in part beta-carotene absorption in humans. Thus, we have studied the effect of different dietary lipids on beta-carotene uptake into mixed micelles in vitro. Using this method, the effects of fatty acids of increasing degrees of unsaturation, vitamin A, cholesterol, and vitamin E on beta-carotene uptake into micelles were studied. Uptake of beta-carotene into micelles was stimulated by cholesterol and unsaturated fatty acids (uptake correlated with degree of unsaturation). beta-Carotene solubilization into micelles was inhibited by vitamin A and vitamin E. These results suggest that the absorption of beta-carotene may be partly regulated at the level of formation of intestinal micelles by the presence of different dietary components.