Positive association between dietary inflammatory index and gastric cancer risk: A systematic review and meta-analysis

Aimed to investigate the association between potential inflammatory diet, determined by the dietary inflammatory index (DII) and gastric cancer (GC) risk, we conducted this systematic review and meta-analysis. MEDLINE, EMBASE and the Cochrane library were searched up to May 2019. Studies reported associations between DII and GC were included. Relative risk (RR) with 95% confidence interval (CI) were synthesized by fixed-effects model. Subgroup analysis stratified by gender was also conducted. To test stability of results, we performed sensitivity analyses and Rosenthal's fail-safe Number for publication bias. We included four studies to explore the association with the DII on the risk of GC. Three of them were employed to pool effect size for subjects with the most pro-inflammatory diet compared with the most anti-inflammatory diet; three for an increment of 1-unit DII. We found potential inflammatory diet increased the risk of GC (most pro-inflammatory diet vs. most anti-inflammatory diet: RR, 1.95, 95%CI, 1.48 to 2.57, I-2 = 42.7%; an increment of 1-unit DII: RR, 1.24, 95% CI 1.12-1.38, I-2 = 84.3%). These results were stable in sensitivity analyses. No publication bias was found. We found that potential inflammatory diet was related to increased risk of GC. Interestingly, the risk is only among male.