ABSTRACT
SCOPE: The concept that dietary factors are key risk and preventive agents in the development of Crohn's disease (CD), while widely believed and supported by epidemiological evidence, has yet to lead to clear identification of those factors through clinical trials. The aims are to examine the strength of the epidemiological evidence of diet and its association with CD, examine how interpretation of mostly epidemiological data has shaped ideas for potential dietary therapies, and to explore other factors that have driven the design of dietary clinical trials in CD. METHODS: A literature search is performed in PubMed, Medline, EMBASE, and Google Scholar for prospective cohort studies and randomized clinical trials (RCTs) using search terms-"Crohn's disease," "diet," "risk," "remission," "treat," "cohort," "randomised." RESULTS: Only four prospective cohort studies examine the relationship of diet and CD development, but these trials have been largely ignored by dietary RCTs in CD, which have used predominantly exclusion diets in small populations without objective endpoint assessment. Only one demonstrated clinical benefit to intestinal inflammation. CONCLUSION: Investment in large multicenter dietary clinical trials that focus on dietary inclusions with objective endpoint assessment are needed to provide safe, sustainable dietary therapy to patients with CD.