Ultraprocessed Grains Increase IBD Risk: AJG | June 2026

• This large prospective PURE study evaluated the relationship between ultraprocessed grain consumption and the future development of inflammatory bowel disease across 124,590 participants from 21 countries.
• Ultraprocessed grains include heavily refined grain products that often contain additives, emulsifiers, preservatives, flavour enhancers, and other industrial ingredients.
• Higher consumption of ultraprocessed grains was associated with a significantly increased risk of developing IBD.
• Individuals consuming ≥19 g/day of ultraprocessed grains had nearly double the risk of IBD compared with those consuming less than 9 g/day.
• The association remained significant after adjustment for major confounders, including age, sex, smoking, dietary habits, and physical activity.
• The findings support growing evidence linking Westernised dietary patterns and food processing to intestinal inflammation.
• In contrast, consumption of fresh bread and rice was associated with a lower risk of developing IBD.
• The study also confirmed a broader dietary signal: higher overall intake of ultraprocessed foods was strongly associated with future IBD development.
• Participants consuming five or more servings of ultraprocessed foods daily had almost a fourfold higher risk of IBD compared with those consuming less than one serving per day.
• Several biological mechanisms may explain the findings, including:

Alteration of gut microbiota

Increased intestinal permeability

Disruption of the mucus barrier

Exposure to food additives and emulsifiers

Enhanced mucosal immune activation

• The study adds further support to the hypothesis that environmental and dietary factors contribute substantially to the rising global incidence of IBD.
• Although observational, the prospective design and multinational nature of the PURE cohort strengthen the validity of the findings.
• The study cannot identify which specific component of ultraprocessed grains is responsible for the increased risk, and further mechanistic research is needed.
• From a clinical perspective, dietary counselling aimed at reducing ultraprocessed food consumption may become an increasingly important component of IBD prevention strategies.

Bottom line: Higher consumption of ultraprocessed grains is associated with a significantly increased risk of developing IBD, while less processed staple foods, such as fresh bread and rice, appear to be associated with lower risk. The findings reinforce the importance of minimising ultraprocessed foods as part of a gut-healthy dietary pattern