Dietary risk factors in Crohn's disease and ulcerative colitis: a cohort study with paired healthy relatives as controls

PurposeConflicting results have been reported on dietary factors in inflammatory bowel diseases (IBDs). Here, we compared the dietary intakes of IBD patients with those of paired healthy relatives (HRs), aiming to minimize the impact of genetic and environmental confounders.MethodsPatients with Crohn's disease (CD, N = 45) and ulcerative colitis (UC, N = 20), their paired HRs (NCD-HR = 45, NUC-HR = 20) and healthy non-relative (HNR, NCD-HNR = 25, NUC-HNR = 55) controls were recruited. Participants have kept dietary habits since the onset of IBDs and report no other recent digestive diseases or surgeries. Pre-illness dietary factors were assessed through 24-hour recall interviews. Statistical analyses included Analysis of Variance, Fisher's exact tests, Wilcoxon rank sum tests, logistic regressions, Area Under the Receiver-Operator Curve (AUROC) analysis, and Least Absolute Shrinkage and Selection Operator (LASSO) regression.ResultsDietary features identified in IBD patients using the HR controls differed from those identified using the HNR controls. For CD, lower intakes of vitamin C, dietary fiber, calcium, vegetables, decanoic acid (10:0), milk, dairy foods, and beta-carotene were identified as risk factors when compared to HRs. LASSO regression highlighted milk, vegetables, and vitamin C as the most significant risk factors for CD. In UC patients, lower intakes of phosphorus, docosapentaenoic acid (DPA, 22:5, n-3), vitamins B-2 and B-12, and choline, along with a higher intake of alpha-carotene, were identified as risk factors compared to HRs. LASSO regression emphasized DPA, vitamins B-2 and B-12, and alpha-carotene as the most significant risk factors for UC.ConclusionMonitoring dietary intake patterns is crucial for the prevention and personalized treatment of CD and UC.