Ultraprocessed grains and risk of inflammatory bowel disease: Results from the prospective urban rural epidemiology study

Abstract

INTRODUCTION: – Ultra-processed 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 ultra-processed 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 ultra-processed 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 ultra-processed grain intake was associated with increased IBD risk. Participants consuming ≥19 g/d of ultra-processed 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 ultra-processed 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 ultra-processed grains is associated with significantly increased risk of developing IBD. A healthy eating pattern should minimize consumption of ultra-processed grains. Further studies should be performed to understand which components of ultra-processed grains may be detrimental for health. © 2025 by The American College of Gastroenterology