Effect of potato starch, cornstarch and sucrose on aberrant crypt foci in rats exposed to azoxymethane

Studies have shown that different kinds of carbohydrates are able to modify the development of colo-rectal cancer in animals as well as humans. In the present study with rats sucrose and two types of starches were investigated for their effects on the development of aberrant crypt foci (ACF), which have been proposed to represent preneoplastic lesions of colorectal cancer. Fifty-six three-week-old male Wistar rats were randomly assigned to four groups and dosed subcutaneously with AOM (15 mg/kg body wt) once a week for 2 weeks. At the end of the dosing period the animals were allocated to their respective diets. Group I was fed the basic diet; in Group II the carbohydrate pool in the diet was replaced by sucrose, in Group III by potato starch and in Group IV by cornstarch. Animals receiving the potato starch diet showed a statistically significant reduction in body weight gain. A statistically significantly lower number of ACF in all categories but small were demonstrated in animals given potato starch, and in addition an effect was seen in the relative distribution of ACF with fewer of the larger ACF. No effect of sucrose or cornstarch was seen. Explanations of the inhibitory effect in the potato starch group on the development of ACF could either be the lower daily caloric intake or the substantial amounts of resistant starch in the potato starch used.