Association between food-based dietary inflammatory potential and ulcerative colitis: a case-control study

Despite several studies on the link between dietary inflammatory potential and risk of several conditions, limited studies investigated the association between pro-inflammatory diet and ulcerative colitis (UC). The objective of the present study was to examine the link between food-based dietary inflammatory potential (FDIP) and odds of UC in Iranian adults. This case-control study was carried out among 109 cases and 218 randomly chosen healthy controls. UC was diagnosed and confirmed by a gastroenterologist. Patients with this condition were recruited from Iranian IBD registry. Age- and sex-matched controls were selected randomly from participants of a large cross-sectional study. Dietary data were obtained using a validated 106-item semi-quantitative food frequency questionnaire (FFQ). We calculated FDIP score using subjects' dietary intakes of 28 pre-defined food groups. In total 67% of subjects were female. There was no significant difference in mean age between cases and controls (39.5 vs. 41.5y; p = 0.12). The median (interquartile range) of FDIP scores for cases and controls were - 1.36(3.25) and - 1.54(3.15), respectively. We found no significant association between FDIP score and UC in the crude model (OR 0.93; 95% CIs 0.53-1.63). Adjustment for several potential confounders in multivariate model did not change this association (OR 1.12; 95% CIs 0.46-2.71). We failed to observe any significant association between greater adherence to a pro-inflammatory diet and risk of UC in this study. Prospective cohort studies are needed to further assess this relationship.