Meta-analysis of the Relationship between Dietary Inflammatory Index and Upper Gastrointestinal Cancer Risks

Background Dietary components can produce a variety of bioactive substances that maintain a low inflammatory state in the body and participate in the formation of the tumor microenvironment. The dietary inflammatory index (DII) is a new indicator to quantify the inflammatory potential of diet. High DII score is closely associated with the risk of colorectal cancer, but its relationship with upper gastrointestinal cancer (UGIC) is unclear. Objective This study was conducted to assess the relationship between DII and the risk of UGIC, providing a scientific basis for dietary guidance. Methods We did a systematic search of PubMed, Web of Science, Embase and the Cochrane Library for studies on the association of DII score and UGIC published in English, and Wanfang Data, CNKI and VIP for those published in Chinese, from inception to October 10, 2022. Two researchers performed literature screening, data extraction, and quality evaluation separately. RevMan 5.4.1 was used for meta-analysis and subgroup analysis. Results A total of 11 case-control studies including 9 051 participants were included in this study. Meta-analysis showed that high DII score were associated with an increase in the risk of UGIC〔OR=1.81, 95%CI (1.65, 1.97), P30) 〔OR=2.01, 95%CI (1.57, 2.57), P