BIOCHEMICAL EPIDEMIOLOGY OF COLON-CANCER - EFFECT OF TYPES OF DIETARYFIBER ON COLONIC DIACYLGLYCEROLS IN WOMEN

Background/Aims: In view of the potential significance of dietary fat and fiber in colon cancer and the possible indirect involvement of dia cylglycerols (DAGs) in the pathogenesis of colon cancer, the effect of types of dietary fiber on fecal DAG in premenopausal women was invest igated. Methods: Forty-eight women consuming a typical western diet pr ovided two 24-hour stool specimens and two sets of preintervention 4-d ay food records. They were randomly assigned to one of the fiber group s, namely, a wheat, oat, or corn bran supplement. They consumed their control diet plus 13-15 g of dietary fiber from each source for 8 week s. At the end of the fiber period, each subject provided two 24-hour s tool specimens and 4-day food records. Stool samples collected during the two periods were analyzed for total fat and DAG fatty acids. Resul ts: All sources of dietary fiber increased the amount of fecal fat exc reted. Dietary wheat bran decreased the concentrations of total DAG an d DAG containing lauric acid, myristic acid, palmitic acid, stearic ac id, and linoleic acid, whereas oat bran increased the DAG composed of oleic acid and linoleic acid compared with the control diet. Corn bran decreased the DAG containing stearic acid. Conclusions: These results show that the modifying effect of dietary fiber on DAG depends on the type of fiber consumed.