Incidence and Growth of Mammary Tumors Induced by 7,12-Dimethylbenz[a]anthracene as Related to the Dietary Content of Fat and Antioxidant 1,2

amount, and the dietary antioxidant butylated hydroxytoluene (BHT) on tumor Induction and tumor growth by 7,12-dlmethyl-benz[a]anthracene was studied. The study was to determine whether Ingestion of polyunsaturated fat decreased or antag-onized the Inhibitory action of the antioxidant In comparison to diets that either contained equivalent amounts of a saturated fat or were very low In fat. The rationale was based on the known Increased requirement for antioxidant caused by elevated levels of dietary unsaturated fat. Because the feeding of excess dietary polyunsaturated fat without an adequate elevation of dietary antioxidant causes various types of tissue Injury In different species, It Is reasonable to consider that the promotional effect of polyunsaturated fat In tumor development may be related to this phenomenon. We have confirmed that Sprague-Dawley female rats fed the high fat diets not only had a higher tumor Incidenc