Ultraprocessed Grains and Risk of Inflammatory Bowel Disease: Results From the Prospective Urban Rural Epidemiology Study

INTRODUCTION: Ultraprocessed grains, commonly consumed in Western diets, undergo refining processes that often remove beneficial components and include additives to enhance taste, texture, or durability, potentially influencing gastrointestinal health. This study examines the association between ultraprocessed grain consumption and the risk of developing inflammatory bowel disease (IBD) using data from the Prospective Urban Rural Epidemiology (PURE) study. METHODS: This analysis included 124,590 participants from 21 countries who had dietary data available in the PURE study. Dietary intake was assessed through validated food frequency questionnaires, and ultraprocessed grain intake was categorized into 3 levels. The primary outcome was the development of IBD, including Crohn's disease (CD) and ulcerative colitis (UC). Multivariate Cox proportional hazard models were used to calculate hazard ratios (HRs), adjusting for confounders including age, sex, smoking status, eating habits, and physical activity. RESULTS: Among 124,590 participants, higher ultraprocessed grain intake was associated with increased IBD risk. Participants consuming ≥19 g/d of ultraprocessed grains had a higher risk of developing IBD compared with those consuming <9 g/d (hazard ratio [HR] 1.86, 95% confidence interval 1.26-2.61, Ptrend = 0.0003) after multivariate adjustment. Fresh bread and rice consumption were associated with lower IBD risk. Participants with greater ultraprocessed food intake (≥5 servings per day) were linked to a higher risk of developing IBD compared with those consuming <1 serving per day (HR 3.95, 95% confidence interval 2.74-5.71, Ptrend < 0.0001). DISCUSSION: Higher intake of ultraprocessed grains is associated with significantly increased risk of developing IBD. A healthy eating pattern should minimize consumption of ultraprocessed grains. Further studies should be performed to understand which components of ultraprocessed grains may be detrimental for health.