Doris Howes Calloway

Reduction of x-radiation mortality by cabbage and broccoli.

Summary Exposure to 400 r of whole-body X-radiation resulted in 100% mortality in 10 to 15 days of young male guinea pigs fed a basal diet of bran and oats plus ascorbic acid. Supplementation with cabbage or broccoli for 2 weeks before irradiation and during 30 days after irradiation significantly reduced mortalty. Lyophilized cabbage retained ability to reduce radiation mortality. Pre-feeding of guinea pigs to time of radiation exposure, signficantly delayed onset of death and enabled some animals to survive test period. Post-irradiation supplementation with cabbage also yielded a lower total mortality. Feeding of cabbage both before and after radiation exposure produced greatest amount of protection.

Further studies of the influence of diet on radiosensitivity of guinea pigs, with special reference to broccoli and alfalfa.

Earlier studies showed that supplementation of a bran and oats diet with cabbage decreased the radiosensitivity of guinea pigs. Attempts were made to elucidate the dietary factors conferring radioprotection on guinea pigs. After maintenance on various diets, they were exposed to 350rad of Co/sup 60/ gamma radiation or 400-r of x radiation. Whole-body exposure to either x or 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. It was shown that supplementation with alfalfa, broccoli, and other plant materials high in content of BETA -carotene, for 2 weeks before irradiation and during 20 to 30 days after irradiation, consistently reduced mortality. Other diets showed marginal or no beneficial effects. Supplementation of the bran-oats diet with pure vitamin A or BETA -carotene extended survival time but did not appreciably influence radiationinduced mortality. Guinea pigs fed an adequate purified diet were more resistant to radiation injury than those given the bran-oats basal diet. Supplementation of the adequate purified diet with broccoli or alfalfa did not constently affect radiosensitivity under these conditions. The beneficial effect of raw broccoli could not be duplicated by feeding themorexa0» bran-oats diet supplemented with a mixture of 48 chemically pure ingredients patterned upon the composition of broccoli. The radioprotective agent in alfalfa is water-soluble and is destroyed upon ashing. Two hynotheses are offered to account for these responses. First, the bran-oats diet may impose a requirement which does not exist with the purified diet, either due to the presence of some substance detrimental to absorption or to a specific nutrient imbalance. Alternatively, an unrecognized essential substance may be provided by both green plant materials and some ingredient of the purified diet. (H.H.D.)«xa0less

Effects of chronic food restriction in swine.

atherosclerosis when cholesterol feeding and undernutrition were combined. In a careful study of the role of undernutrition upon cholesterol-induced atherosclerosis in rabbits, McMillan et al. (54) observed that food restriction favored hypercholesterolemia but did not change the incidence of aortic atherosclerosis. The experiment reported here was per formed to determine the effects of under feeding a human diet on common param eters of lipid metabolism and vascular pathology of swine. This species was selected because obesity develops early in life; vascular lesions occur spontaneously (Gottlieb and Lalich, 54); and blood lipo-