ObjectivesTo systematically review the association between pepper consumption and risk of gastric cancer.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, WanFang Data, VIP and CNKI databases were electronically searched to collect epidemiological studies of evaluating the association between pepper consumption and the risk of gastric cancer from inception to April, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 12.0 software.ResultsA total of 18 studies involving 17 case-control studies and 1 cohort study with 13 142 participants were included. The studies were divided into quantitative group and non-quantitative group. The results of meta-analysis showed that: ① In quantitative group, medium to heavy pepper consumption was the risk factor of gastric cancer (OR=1.55, 95%CI 1.13 to 2.14, P=0.008). Whereas there was no significant association between low pepper consumption and the risk of gastric cancer (OR=0.63, 95%CI 0.26 to 1.50, P=0.297). ② In the non-quantitative group, pepper consumption was the risk factor of gastric cancer (OR=1.37, 95%CI 1.09 to 1.74, P=0.008). ③ Subgroup analysis results showed that medium to heavy pepper consumption in Asian population had significant association with gastric cancer (OR=2.24, 95%CI 1.88 to 2.67, P=0.005), however, there was no significant association between low pepper consumption and the risk of gastric cancer (OR=0.62, 95%CI 0.33 to 1.18, P=0.144).ConclusionsThe association between pepper consumption and risk of gastric cancer remains unclear, medium to heavy pepper consumption may be related to the risk of gastric cancer, especially in Asian population.