Effect of dietary lipids on hepatic and plasma beta-carotene and vitamin A levels in rats fed beta-carotene.

Diets low in carotenoids have been associated with greater risks of developing certain cancers. Diets high in fats, especially unsaturated fats, have also been associated with increased risks of developing cancer. This study was undertaken to evaluate the effect of fat type on the beta-carotene status in a rat model. Rats were fed diets containing 2 g/kg beta-carotene or placebo and either 10% lard or corn oil for 13-16 weeks. Plasma vitamin A was unaffected by the dietary regimes. Liver vitamin A levels were significantly increased in the beta-carotene groups and were greater in the lard-fed animals. No detectable level of plasma beta-carotene was found in the rats fed placebo diets. In animals given dietary beta-carotene, plasma beta-carotene levels were significantly reduced in the group fed corn oil compared to the group fed lard. Liver beta-carotene levels were higher in the groups fed corn oil. The results suggest that the type of dietary fat can significantly affect the circulating and tissue levels of beta-carotene.