Supplementary Material for: Consumption of Sugar-sweetened Soft Drinks and Risk of Gastrointestinal Cancer: A Systematic Review and Meta-analysis of Observational Studies

Introduction: Previous observational studies have reported inconsistent findings on the association between consumption of sugar-sweetened soft drinks (SSSDs) and the risk of gastrointestinal (GI) cancer. This study investigated the associations between SSSD consumption and the risk of GI cancer using a systematic review and meta-analysis. Methods: Observational epidemiological studies were searched from the PubMed and EMBASE databases until June 2021. We conducted a meta-analysis of all included studies and subgroup meta-analyses based on various factors. Results: In a meta-analysis of 27 studies with nine case-control studies and 18 cohort studies, the consumption of SSSDs was modestly associated with an increased risk of GI cancer (OR/RR: 1.08; 95% CI, 1.01-1.16), with a significant positive dose-response relationship. In the subgroup meta-analysis by study design, there was a significant positive association between the consumption of SSSDs and GI cancer in cohort studies (RR, 1.11; 95% CI, 1.03-1.20; n = 18), but not in case-control studies. In the subgroup meta-analysis by type of cancer, consumption of SSSDs was significantly associated with an increased risk of colorectal cancer (OR/RR: 1.13; 95% CI, 1.07-1.19). Conclusions: This meta-analysis suggests that SSSD consumption significantly increases the risk of GI cancer, specifically colorectal cancer.

前言：既往观察性研究针对含糖软饮料（sugar-sweetened soft drinks (SSSDs)）摄入与胃肠道（gastrointestinal (GI)）癌症风险的关联所得结论并不一致。本研究通过系统评价与荟萃分析（meta-analysis），探究了含糖软饮料摄入与胃肠道癌症风险之间的关联。方法：检索截至2021年6月的PubMed及EMBASE数据库中收录的观察性流行病学研究。我们对纳入的全部研究开展了荟萃分析，并基于多类因素进行了亚组荟萃分析。结果：针对纳入27项研究（含9项病例对照研究与18项队列研究）的荟萃分析显示，含糖软饮料摄入与胃肠道癌症风险升高呈轻度关联（比值比/相对风险：1.08；95%置信区间：1.01~1.16），且存在显著的正向剂量-反应关系。按研究设计开展亚组荟萃分析时，队列研究显示含糖软饮料摄入与胃肠道癌症风险呈显著正相关（相对风险：1.11；95%置信区间：1.03~1.20；n=18），但病例对照研究未观察到该关联。按癌症类型进行亚组荟萃分析时，含糖软饮料摄入与结直肠癌风险升高显著相关（比值比/相对风险：1.13；95%置信区间：1.07~1.19）。结论：本项荟萃分析表明，含糖软饮料摄入会显著升高胃肠道癌症风险，尤以结直肠癌风险为显著。