Dietary habits as risk factors for inflammatory bowel disease.

To examine the influence of dietary factors in Italian patients with ulcerative colitis and Crohn's disease. We studied dietary habits immediately prior to the onset of disease in 104 patients enrolled in a prospective, epidemiological study of the incidence of inflammatory bowel disease in Italy. Each patient was interviewed using a recall questionnaire to provide information on the daily intake of nutrients. The differences in diet between patients and healthy subjects matched for age, sex and city of residence were determined. Our data confirm that patients with Crohn's disease and ulcerative colitis have a high intake of total carbohydrate, starch and refined sugar. This resulted in a significantly higher relative risk (P < 0.001) in both ulcerative colitis and Crohn's disease patients. Total protein intake was significantly higher in ulcerative colitis, but not in Crohn's disease patients, than in controls. Fibre consumption did not differ between patients and controls. Our results confirm that carbohydrate consumption is significantly higher in IBD patients than in healthy controls. Ulcerative colitis patients also consumed more total protein than controls. The pathogenetic significance of these findings, however, remains unclear.