Association of Dietary Cholesterol Intake With Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Observational Studies

Many case-control studies have investigated the association between dietary cholesterol and gastric cancer, yielding inconsistent findings. We carried out a systematic review and meta-analysis of observational studies to assess the relationship between dietary cholesterol intake and gastric cancer among adults. PubMed, Scopus, and Google Scholar were systematically searched to identify articles that evaluated the association of dietary cholesterol with gastric cancer up to May 2021. Pooled odds ratio (ORs) and 95% confidence intervals (CIs) were computed using random-effects models. Dose-response analysis was used to explore the shape and strength of the association. Fourteen case-control studies with 6,490 gastric cancer patients and 17,793 controls met our inclusion criteria. In the meta-analysis of the highest vs. the lowest dietary cholesterol categories, a significantly higher (~35%) risk of gastric cancer was observed in association with high cholesterol consumption (pooled OR: 1.35, 95% CI: 1.29-1.62, = 68%; 95%CI: 45-81%). Subgroup analysis also showed this positive relationship in population-based case-control studies, those conducted on non-US countries, those with a higher number of cases and high-quality studies, those that collected dietary data via interviews, studies not adjusted for infection, and studies where the body mass index was controlled. Besides, a non-linear dose-response association was also identified ( = 0.03). This study demonstrated that dietary cholesterol intake could significantly augment the risk of gastric cancer in case-control studies. Prospective cohort studies with large sample sizes and long durations of follow-up are required to verify our results.