A high-fiber diet may improve bowel function and health-related quality of life in patients with Crohn disease

Abstract

Crohn disease is a chronic disorder characterized by episodes of epithelial inflammation in the gastrointestinal tract for which there is no cure. The prevalence of Crohn disease increased in civilized nations during the time period in which food sources were industrialized in those nations. A characteristic of industrialized diets is the conspicuous absence of cereal fiber. The purpose of this 2-group, randomized, controlled study was to investigate the effects of fiber-related dietary instructions specifying wheat bran consumption on health-related quality of life and gastrointestinal function in individuals diagnosed with Crohn disease, as measured by the Inflammatory Bowel Disease Questionnaire and the partial Harvey Bradshaw Index, respectively. Results demonstrated that consuming a wheat bran-inclusive diet was feasible and caused no adverse effects, and participants consuming whole wheat bran in the diet reported improved health-related quality of life (p = .028) and gastrointestinal function (p = .008) compared to the attention control group. The results of a secondary aim, to investigate differences in measures of systemic inflammation, found no group differences in C-reactive protein or erythrocyte sedimentation rates. This study suggests that diet modification may be a welcomed complementary therapy for individuals suffering gastrointestinal disruption associated with Crohn disease.

Figure 1. Inflammatory Bowel Disease Questionnaire (IBDQ) Scores During Study

The IBDQ measures Crohn’s disease-specific health-related quality of life related to bowel symptoms, systemic symptoms, emotional function, and social function. All participants in both groups began the study under the cutoff point for clinical remission (≥170 points). Participants in the intervention group achieved clinical remission by week 2 and continued to improve substantially through the end of the study period. Scores for participants in the active intervention group increased by 44 points, an increase exceeding the change in score considered to be a clinically significant response (≥32-point change). The control group improved by 19 points, an increase not considered to be clinically significant.

Figure 2. Partial Harvey Bradshaw Index Graph (pHBI)

The pHBI measures Crohn’s disease symptoms (general well-being, abdominal pain, and liquid stools). This graph shows that the high fiber (bran) treatment group and the control group mean scores were close at baseline. Mean scores for both groups dropped during the first week, the intervention group dropping more steeply. From week 1 until the end ot the study, the control group means did not drop further and in fact increased slightly. Because all participants in the intervention group scored a ‘zero’ on the pHBI at week 4, the pHBI scores were transformed by adding 0.5 to allow analysis.