SUPPRESSION OF THE PROMOTER EFFECT OF POLYUNSATURATED FATTY-ACIDS BY THE ABSENCE OF DIETARY VITAMIN-E IN EXPERIMENTAL MAMMARY-CARCINOMA

Because lipoperoxides seem able to modulate tumor growth, we have exam ined the concomitant effects of dietary antioxidant (vitamin E) and of a high amount of polyunsaturated fatty acids (PUFA) in a model of che mically-induced mammary carcinogenesis. Two groups of rats received a high fat diet with or without added vitamin E and mammary tumors were initiated in both groups by an injection of carcinogen. Tumor growth w as followed in both groups. We found that tumor incidence and growth w ere decreased in rats with no added vitamin E in diet, suggesting a pr otective role of oxidized PUFA at later stages of carcinogenesis. (C) 1997 Elsevier Science Ireland Ltd.