The effect of wheat class and processing on markers of colon cancer risk in carcinogen-treated rats.

摘要

A previous study in this laboratory found that hard red wheat is more effective than soft white wheat in reducing colon cancer risk, regardless of processing state, based on fewer aberrant crypt foci (ACF), a morphological marker of colon cancer risk. Here we examined the effect of wheat class (red vs. white) and processing (whole vs. refined) on reducing markers of colon cancer risk during the early and late promotion stage of colon cancer development. Rats adapted to a basal diet were treated twice with the colon-specific carcinogen, dimethylhydrazine (DMH). After the last dose of carcinogen, rats were divided into either the basal diet or the wheat flour-based diet groups. Both hard red and soft white wheat flour significantly reduced morphological markers such as ACF, and sialomucin producing ACF (SiM-ACF), an ACF with greater tumorigenic potential, compared to the basal diet. These reductions occurred equally with whole and refined wheat. Both hard red and soft white wheat diets significantly reduced a biochemical marker of risk, beta-catenin accumulated crypts (BCAC), compared to the basal diet, but hard red wheat did so to a greater degree. Only hard red wheat significantly reduced a marker of stem cells mutation, metallothionein positive crypts, compared to soft white wheat. Hard red wheat caused regression of ACF, suggesting it can reduce the risk level of colon cancer. Overall, hard red wheat reduced colon cancer risk more than soft white wheat, regardless of processing state. The differences between wheat flours were greater in the late promotion stage.