Dietary Inflammatory Potential and Risk of Crohn's Disease and Ulcerative Colitis.

BACKGROUND & AIMS: Inflammation is a potential mechanism through which diet modulates the onset of inflammatory bowel disease. We analyzed data from 3 large prospective cohorts to determine the effects of dietary inflammatory potential on the risk of developing Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

We collected data from 166,903 women and 41,931 men in the Nurses' Health Study (1984-2014), Nurses' Health Study II (1991-2015), and Health Professionals Follow-up Study (1986-2012). Empirical dietary inflammatory pattern (EDIP) scores were calculated based on the weighted sums of 18 food groups obtained via food frequency questionnaires. Self-reported CD and UC were confirmed by medical record review. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

We documented 328 cases of CD and 428 cases of UC over 4,949,938 person-years of follow-up. The median age at IBD diagnosis was 55 years (range 29-85 years). Compared with participants in the lowest quartile of cumulative average EDIP score, those in the highest quartile (highest dietary inflammatory potential) had a 51% higher risk of CD (HR 1.51; 95% CI 1.10-2.07; P = .01). Compared with participants with persistently low EDIP scores (at 2 time points, separated by 8 years), those with a shift from a low to high inflammatory potential of diet or persistently consumed a proinflammatory diet had greater risk of CD (HR 2.05; 95% CI 1.10-3.79 and HR 1.77; 95% CI 1.10-2.84). In contrast, dietary inflammatory potential was not associated with the risk of developing UC (P = .62).

CONCLUSIONS

In an analysis of 3 large prospective cohorts, we found dietary patterns with high inflammatory potential to be associated with increased risk of CD but not UC.