Comparison of dietary carbohydrates for promotion of DMBA-induced mammary tumorigenesis in rats.

Epidemiologic studies have suggested that sugar consumption is correlated with risk of breast cancer. We tested this possibility using the 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumor rat model. Rats were fed diets containing one of three carbohydrates: sucrose, lactose, or corn starch. Tumor yields were similar in the groups fed sucrose and corn starch but significantly lower in the animals fed lactose. Consumption of starch was associated with the most palpable tumors which weighed significantly more than tumors from the other groups. These data indicate significant effects on promotion of mammary tumorigenesis by dietary carbohydrates.