Tumors in female offspring of control and diethylstilbestrol-exposed mice fed high-fat diets.

Strong correlations have been established internationally between female reproductive system cancer rates and dietary fat. To test the hypothesis that the prenatal period is a critical time for exposure to high dietary fat, we placed adult female strain CD-1 mice with or without prenatal exposure to diethylstilbestrol (DES) on diets with low or high levels of fat and mated them. After delivery of the litters, these mice were given the commercial diet on which they had been raised. Their female offspring were raised on this commercial diet until terminal illness occurred. Of the 47 offspring of control mice on low-fat diets, only five had reproductive system tumors, whereas tumors developed in 39 of 78 offspring of mice on high-fat diets. For DES-exposed mice, tumors developed in 18 of 64 offspring of mice on low-fat diets and 38 of 70 offspring of mice on high-fat diets. Nine mice with metastatic mammary tumors and seven with pituitary tumors were offspring of mice on high-fat diets.