Introduction: Dairy consumption has been linked to the development of autoimmune diseases. We aimed to examine the association between dairy intake and risk of incident inflammatory bowel disease (IBD). Methods: We conducted a prospective cohort study of 197,763 participants without a baseline diagnosis of IBD in 1986 in Nurses’ Health Study (NHS), 1991 in Nurses’ Health Study II (NHSII), and 1986 in Health Professionals Follow-up Study (HPFS). Data on dairy intake were collected every 2-4 years using a validated semi-quantitative food frequency questionnaire and modeled according to quintiles for total intake and quartiles for components of dairy. We used Cox proportional hazard modeling to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). Results: Through the end of follow up in 2016 in NHS and HFPS, and 2017 in NHSII, we documented 347 Crohn’s disease (CD) cases and 428 cases of ulcerative colitis (UC). In our primary analysis, we observed an inverse association between baseline dairy intake (P trend =0.04) and risk of UC (aHR of 0.72 (95%CI 0.52-1.00 comparing extremes of quintiles). Among dairy components, baseline yogurt consumption (HR=0.70; 95%CI 0.5-0.99; P trend =0.05) was most strongly associated with decreased risk of UC. There was no consistent association between dairy intake and risk of CD. Conclusion: In three large prospective cohort studies, we observed a suggestive inverse association between baseline dairy intake, particularly from yogurt, and risk of UC. Future studies are needed to confirm these results.
Sasson et al. (Tue,) studied this question.