A SIGMOIDOSCOPY-BASED CASE-CONTROL STUDY OF POLYPS - MACRONUTRIENTS, FIBER AND MEAT CONSUMPTION

We conducted a large, sigmoidoscopy-based case-control study to examin e the relation of intake of macronutrients, meat, and fiber to occurre nce of adenomas of the large bowel. Cases were subjects diagnosed for the first time with one or more histologically confirmed adenomas. Con trols had no polyps of any type at sigmoidoscopy, had no history of po lyps, and were individually matched to cases by gender, age, date of s igmoidoscopy, and Kaiser Center. The response rate was 84% for cases a nd 82% for controls. Complete dietary data for 488 matched pairs were available. All odds ratios are from matched analyses adjusted for ener gy. We observed positive associations with risk of adenomas for calori es, animal fat, saturated fat, red meat, and the ratio of red meat to poultry and fish. protective effects were observed for vegetable prote in, carbohydrates, and dietary fiber. The fiber effects diminished aft er adjusting for fruits and vegetables. Results after mutually adjusti ng for the effects of saturated fat, fiber and the ratio of red meat t o chicken and fish suggest that each of these variables has an effect on risk of adenomas that is independent of the other 2 exposures. (C) 1997 Wiley-Liss, Inc.