In contrast to the limited number of human interventions evaluating dietary resistant starch, several studies
have been done on the impacts of resistant starch and colon
cancer prevention in laboratory animals. Le Leu et al.
(67,135,136) conducted extensive studies in rats treated
with the colon carcinogen azoxymethane and/or fed diets
high in protein to damage the colonic epithelium. Feeding
high fiber or resistant starches increased fecal bulk, fecal
pH, butyrate concentration, and epithelial apoptosis, and
it decreased cell proliferation markers and colon carcinogenesis. When animals were fed high levels of protein, the
addition of high-amylose resistant starch reduced protein
fermentation products, which paralleled reduced colorectal carcinoma development. In contrast to these findings,
studies with potato fiber or potato resistant starch in rats
fed control protein or high-protein diets revealed no impact of dietary resistant starches on DNA damage in the
colon (137).