Dietary Patterns and Risk of Inflammatory Bowel Disease: A Systematic Review of Observational Studies

Background The incidence of inflammatory bowel disease (IBD) is increasing worldwide. Dietary patterns may be associated with odds of this disease. Although previous reviews have attempted to summarize the evidence in this field, the growing body of investigations prompted us to conduct an updated comprehensive systematic review.Methods We used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to evaluate the association between dietary patterns before disease onset and the risk of IBD. PubMed, SCOPUS, and Web of Science were searched using structured keywords up to November 20, 2023.Results Twenty-four publications (13 case-control, 1 nested case-control, and 10 cohort studies) were included in this review. The sample size of these studies ranged from 181 to 482 887 subjects. The findings were inconsistent across the included studies, showing inverse, direct, or no association between different dietary patterns and the risk of IBD.Conclusions This review provides comprehensive data on the link between dietary patterns prior to IBD diagnosis and risk of this condition. The explicit finding of present review is the extent gap in our knowledge in this field. Therefore, large-scale, high-quality studies are warranted to improve our understanding of the relationship between dietary patterns and IBD risk. Despite growing studies that have investigated the relationship between diet and inflammatory bowel disease (IBD), a definite conclusion has not been reached yet. In the present review, we summarized previous evidence on dietary patterns linked to risk of IBD to update the current knowledge in this field.