Does the inflammatory potential of diet affect disease activity in patients with inflammatory bowel disease?

Background Diet is an important modulator of inflammation, which is associated with inflammatory bowel disease (IBD). In this study, we examined whether the inflammatory properties of diets are associated with disease activity in patients with IBD. Methods A cross-sectional study was conducted on 143 IBD patients, including 32 patients with Crohn's disease (CD) and 111 patients with ulcerative colitis (UC). Dietary intakes were assessed by a valid 168-item food frequency questionnaire (FFQ). The inflammatory potential of the diet was assessed by calculating the two scores of Dietary Inflammatory Index (DII (R)), and the Empirical Dietary Inflammatory Pattern (EDIP), and CD and UC disease activity were determined by the Crohn's disease activity index (CDAI) and the Mayo score, respectively. Associations of the inflammatory indices as median and as tertiles with disease activity were analyzed using logistic regression in a univariate model and after adjusting for total energy intake (continuous), type of disease (CD and UC) and drug consumption (no drugs, single drug, and multiple drugs). Results Sixty-four IBD patients (44.8%) in this study had active disease.The DII (R) score and the EDIP did not differ significantly between active and inactive patients (- 1.45 +/- 1.04 vs.- 1.20 +/- 1.24; 0.56 +/- 0.22 vs. 0.53 +/- 0.28, respectively). After adjusting for energy intake, drug use, and IBD type, the odds (95%CIs) of active disease among patients in tertile 3 compared to those in tertile 1 were 0.84 (0.32-2.17) for DII and 1.50 (0.61-3.72) for EDIP; neither of which were statistically significantly different from the rates in tertile 1. Conclusions Although point estimates were in the expected direction of increased risk, the inflammatory potential of diet, assessed using DII or EDIP, was not associated with severity of disease in IBD patients. Whether diet-related inflammation affects disease activity in patients with IBD deserves further investigations.