The correlation between chili pepper consumption and gastric cancer risk: A meta-analysis

Background and objectives The correlation between chili pepper intake and gastric cancer (GC) risk has been controversial. We conducted a meta-analysis of 16 studies to provide updated evidence for this uncertainty. Methods and study design Medline, and China National Knowledge Infrastructure (CNKI) databases were searched to obtain all qualified literature related to pepper consumption and GC incidence before June 2020. Random effects models were adopted to integrate the relative risk of individual studies. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the literature of each included study. Dose response meta-analysis was implemented through the one-stage robust error meta-regression (REMR) approach. Results 16 studies (8337 cases) were included in quantitative meta-analysis. The pooled odds ratio (OR) of GC for the highest versus the lowest category of chili consumption were 1.51 (95% confidence interval [CI]=1.02-2.00) for all countries, 2.05 (95% CI=1.15-2.95) for Mexican, 2.03 (95% CI =0.71-3.34) for Colombian, 1.92 (95% CI=1.21-2.64) for Asian and 0.48 (95% CI=0.24-0.72) for other countries. Dose-response meta-analysis showed that there was a positive linear correlation between the risk of GC and the daily frequency of chili consumption. Conclusions Significantly increased consumption of chili pepper or capsaicin has the potential to increase the risk of gastric cancer, however, inconsistencies still exist in subgroup analysis between different regions.