Delay of diethylnitrosamine-induced hepatoma in rats by carrot feeding.

Carcinogenesis and death caused by diethylnitrosamine(DENA)-induced hepatomas in Sprague Dawley rats can be significantly delayed by feeding only carrots for several days a week. As this result is not obtained by supplementing food with even higher concentrations of synthetic beta-carotene, there must be several other factors which--together with the carotenoid--contribute to the positive effect. Several other possibilities such as effects of fasting, direct interactions with the carcinogen, resorption, vitamin A storage in the liver, etc., are proposed and discussed.