Caffeine and IBD - JGH Feb 26

This is the first comprehensive meta-analysis examining the relationship between caffeine intake and inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), synthesising data from 21 studies (13,209 participants).

Overall, caffeine intake was not significantly associated with total IBD risk. However, important differences emerged in subgroup analyses.

For ulcerative colitis, caffeine—particularly from coffee and tea—was associated with a reduced risk, especially in Asia and Europe. Coffee reduced UC risk by 57%, and tea by 46%. In contrast, in the Americas, caffeine intake was associated with an increased UC risk.

For Crohn’s disease, no overall association was observed. However, in smokers, caffeine intake increased CD risk by 80%, whereas in non-smokers, the association was neutral or potentially protective. Education level also influenced findings, suggesting lifestyle and socioeconomic confounding.

Age was a critical modifier: in individuals ≤18 years, caffeine was associated with markedly increased IBD risk, whereas in adults, the association was neutral to slightly protective.

Clinical implications: The relationship between caffeine and IBD appears context-dependent—varying by age, geography, smoking status, and caffeine source. Blanket recommendations are inappropriate. Instead, clinicians should individualise advice, particularly for adolescents and smokers. Further dose-response and mechanistic studies are needed to clarify causality.