DIETARY FIBER AND RISK OF BENIGN PROLIFERATIVE EPITHELIAL DISORDERS OF THE BREAST

Following a recent finding, from a case-control study in Adelaide, South Australia, of a reduced risk of breast cancer among women consuming diets rich in fiber, the fiber densities in the diets of 354 women with incident benign proliferative epithelial disorders of the breast (BPED) were compared with the fiber densities of the diets of 354 matched community controls and with those of 189 unmatched controls having breast conditions for which there was no evidence of BPED at biopsy. Fiber intakes were estimated by means of a self-administered quantitative food-frequency questionnaire, and the risk of BPED war estimated for each quintile of fiber density (grams of fiber/megaJoule of total energy intake) relative to an arbitrarily assigned risk of one for the lowest quintile. For women with the highest dietary fiber densities the estimated risk was 0.64 (95% CI 0.34, 1.19) when cases were compared with community controls, and 0.45 (95% CI 0.24, 0.82) when cases were compared with biopsy-negative controls. Similar trends in risk were observed for the intakes of other major fiber components, the association being stronger when the comparison was made with biopsy-negative as opposed to community controls. If these findings can be substantiated, they may open the way to dietary intervention strategies for reducing the incidence of breast cancer. (C) 1995 Wiley-Liss, Inc.