Effect of high hemicellulose corn bran in 1,2-dimethylhydrazine-induced rat intestinal neoplasia.

The incidence, distribution, size and histopathology of colonic tumors induced by parenteral administration of 1,2-dimethylhydrazine were examined in rats fed a chemically-defined fiber-free diet or a diet containing 4.5% refined high hemicellulose corn bran with equivalent ratios of calories derived from fat, protein and carbohydrate. At an initial sacrifice period, reduced numbers of tumors were observed; however, at a later time period, no statistical differences were present compared to the fiber-free diet group. This study indicates that a high hemicellulose fiber source is protective in this animal model of experimental colonic neoplasia but this appears to reflect only a time-dependent delay in tumor detection or appearance.