This project involved a systematic literature review of published trials of cereal or grain in relation to the risk of gastric cancer. Data was extracted from the publications on PubMed, EMBASE, Cochrane Library.A traditional meta-analysis, subgroup analysis, and heterogeneity was conducted on the extracted data.

Investigators searched PubMed, EMBASE, Cochrane Library for studies focusing on cereal or grain in relation to the risk of gastric cancer up to October 2017. Summary odd ratios (OR) and 95% confidence intervals (CI) were calculated by using either random effect models or fixed effect models according to the heterogeneity of included studies. Subgroup analysis, heterogeneity, and publication bias were also performed.

Inclusion Criteria:

• a case-control studies or a cohort study
• investigate the association between cereal or grain intake and GC occurrence
• report an odds ratio (OR) or relative risk (RR) with corresponding 95% confidence intervals (CI)
• provide sufficient data to estimate OR or RR

Exclusion Criteria:

• Non-human studies
• GC mortality-based cohort studies

All individuals, both children and adults, regardless of health status