The effects of dietary taurocholate, fat, protein, and carbohydrate on the distribution and fate of dietary β‐carotene in ferrets

Abstract

Dietary β‐carotene has been shown to have cancer chemopreventive action on the basis of epidemiologic evidence and studies in animals. Because the anticarcinogenic property of β‐carotene may be exerted per se, it is desirable to achieve the maximum absorption and accumulation of intact β‐carotene in various parts of the body. Therefore the effects of dietary taurocholate, fat, protein, and carbohydrate on the absorption, accumulation, and fate of dietary β‐carotene (3,730 nmollg diet) in selected tissues of ferrets were explored. Taurocholate (0.2–1.0% wt/wt) and fat (6–23% wtlwt) caused two‐ to threefold (p < 0.05) increases in the absorption and accumulation of β‐carotene in the liver, lungs, and adipose tissue in a dose‐dependent manner. In contrast, neither dietary protein (10–40% wt/wt) nor carbohydrate (25–55% wt/wt) affected the absorption and accumulation of p‐carotene in various tissues. Significantly, taurocholate, 23% fat, or 40% protein also markedly increased the amounts of hepatic retinol and retinyl esters derived from dietary p‐carotene. These results indicate that dietary taurocholate, fat, and high protein have a marked influence on the exposure of P‐carotene to intestinal carotene cleavage enzyme or its activity. Thus an ideal combination of dietary components (wtlwt) in ferrets for the maximal absorption and accumulation of β‐carotene in different tissues is 0.5% taurocholate and 13.4% fat, whereas 1% taurocholate, 23% fat, or 40% protein stimulates its conversion to vitamin A.