Aligning patient and planetary health: planetary health diet adherence and inflammatory bowel disease prognosis across Western and Eastern cohorts

This study aims to evaluate whether planetary health diet (PHD) could be a potential tool to achieve sustainability in IBD management. We included 1455 IBD participants from the UK Biobank (UKB) and 205 from the ONE-IBD cohort. Dietary intake was captured through validated questionnaires and seven PHD adherence algorithms were evaluated. Environmental impact was estimated using dietary carbon footprints. Outcomes included IBD-related surgery, colorectal cancer, and all-cause mortality in the UKB, while readmission and recurrence in ONE-IBD. Cox models estimated hazard ratios (HRs) with 95% confidence intervals (CIs). During a median 10.5-year follow-up, 191 surgeries, 78 CRC, and 232 deaths occurred. Adherence to PHD were inversely associated with surgery risk (HR per SD 0.67–0.80). All algorithms were linked to lower dietary carbon footprints (r −0.061 to −0.468). A modified-Knuppel algorithm provided similar protection (HR per SD = 0.73, 95% CI 0.60-0.89) and environmental correlation ( r = −0.244). In ONE-IBD, the modified algorithm was associated with lower readmission risk (HR per SD = 0.80, 95% CI 0.65–1.00). Proteomics data suggest potential benefits through improved intestinal barrier integrity and reduced fibrosis. To conclude, higher PHD adherence is associated with better IBD outcomes and lower environmental burden, supporting that the PHD may represent a promising and sustainable dietary pattern in IBD management.