Further Studies of the Influence of Diet on Radiosensitivity of Guinea Pigs, with Special Reference to Broccoli and Alfalfa

Abstract

Whole-body exposure to X-radiation or Co⁵⁰-gamma radiation resulted in almost total mortality within 10 to 15 days among young guinea pigs fed a basal diet of bran and oats plus ascorbic acid. In confirmation and extension of previous observations, it was shown that supplementation with alfalfa, broccoli, and other plant materials high in content of β-carotene, for two weeks before irradiation and during 20 to 30 days after irradiation, consistently reduced mortality. Other categories of foods showed marginal or no beneficial effects. Supplementation of the bran-oats diet with pure vitamin A or β-carotene extended survival time but did not appreciably influence radiation-induced mortality. Guinea pigs fed an adequate purified diet were more resistant to radiation injury than those given the bran-oats basal diet. Supplementation with broccoli or alfalfa did not consistently affect radiosensitivity under these conditions. The beneficial effect of supplementation with raw broccoli could not be duplicated by feeding a mixture of 48 chemically-pure ingredients patterned upon the composition of broccoli, in conjunction with the bran-oats diet. The radioprotective agent in alfalfa is water-soluble and is destroyed upon ashing.