(HealthDay)—Long-term intake of dietary fiber is associated with a reduced risk of Crohn's disease (CD), but not ulcerative colitis (UC), according to a study published in the November issue of Gastroenterology.
Ashwin N. Ananthakrishnan, M.B.B.S., M.P.H., from Massachusetts General Hospital and Harvard Medical School in Boston, and colleagues collected and analyzed data from 170,776 women who participated in the Nurses' Health Study and were followed for 3,317,425 person-years. A validated semi-quantitative food frequency questionnaire was administered every four years to ascertain dietary information. Medical record review confirmed self-reported CD and UC.
The researchers confirmed 269 and 388 incident cases of CD and UC, respectively (incidence, 8 and 10 per 100,000 person-years, respectively). Intake in the highest (median, 24.3 g/day) versus the lowest quintile of energy-adjusted cumulative average intake of dietary fiber correlated with about a 40 percent reduction in the risk of CD (multivariate hazard ratio for CD, 0.59; 95 percent confidence interval, 0.39 to 0.90). The greatest apparent reduction was seen for fiber derived from fruits, while risk was not modified by fiber from cereals, whole grains, or legumes. Neither total intake of dietary fiber (hazard ratio, 0.82; 95 percent confidence interval, 0.58 to 1.17) nor intake of fiber from specific sources appeared to be significantly associated with risk of UC.
"Based on data from the Nurses' Health Study, long-term intake of dietary fiber, particularly from fruit, is associated with lower risk of CD but not UC," the authors write. "Further studies are needed to determine the mechanisms that mediate this association."
Several authors disclosed financial ties to the pharmaceutical and diagnostics industries.
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