To Örebro University

BACKGROUND & AIMS: Diet is thought to play a role in the development of inflammatory bowel disease (IBD), though the relationship between gluten intake and risk of IBD has not been explored. The aim of this study was to determine the relationship between gluten intake and risk of incident Crohn's disease (CD) and ulcerative colitis (UC).

METHODS: We performed a prospective cohort study of 208,280 US participants from the Nurses' Health Study (NHS; 1986-2016), NHSII (1991-2017), and Health Professionals Follow-up Study (1986-2016) who did not have IBD at baseline or celiac disease, and who completed semi-quantitative food frequency questionnaires. We used Cox proportional hazards modeling to estimate the risk of IBD according to quintiles of cumulative average energy-adjusted dietary gluten intake over follow-up period.

RESULTS: We documented 337 CD cases and 447 UC cases over 5,115,265 person-years of follow-up evaluation. Dietary gluten intake was not associated with risk of IBD. Compared with participants in the lowest quintile of gluten intake, the adjusted hazard ratios and 95% CIs for participants in the highest quintile of gluten intake were 1.16 (95% CI, 0.82-1.64; P-trend = .41) for CD and 1.04 (95% CI, 0.75-1.44; P-trend = .64) for UC. Adjusting for primary sources of gluten intake did not materially change our estimates.

CONCLUSIONS: In three large adult US prospective cohorts, gluten intake was not associated with risk of CD or UC. Our findings are reassuring at a time when consumption of gluten has been increasingly perceived as a trigger for chronic gastrointestinal diseases.