Background and objectives: Coffee is one of the most widely consumed beverages worldwide, and many studies have investigated the association between coffee consumption and gastric cancer. However, the results are inconsistent. We conducted a systematic analysis of relevant population studies to derive a more precise estimation.
Methods and study design: Cochrane library, PubMed and Embase databases were searched to identify studies that met predetermined inclusion criterion through July 2014. All epidemiologic studies regarding coffee consumption and gastric cancer risk were selected, and relative risks (RRs) with 95% confidence intervals (CIs) were calculated.
Results: Twenty two studies (9 cohort and 13 case-control studies) involving 7,631 cases and 1,019,693 controls were included. The summary RR of gastric cancer was 0.94 (95% CI: 0.80-1.10) for the highest category of coffee consumption compared with the lowest category, and 0.93 (95% CI: 0.88-0.99) for coffee drinkers compared with nondrinkers. We stratified the population by coffee consumption. The pooled RR for the population with <1 cup/day, 1-2 cups/day and 3-4 cups/day coffee consumption compared with nondrinkers were 0.95 (95% CI: 0.84-1.08), 0.92 (95% CI: 0.82-1.03) and 0.88 (95% CI: 0.76-1.02), respectively, indicating that an increase in coffee consumption was associated with a decreased risk of gastric cancer. Furthermore, we stratified the studies by design, sex, population and time. A significant association between coffee intake and decreased gastric cancer risk was shown in case-control studies (RR=0.85, 95% CI: 0.77-0.95) and among the studies published over the last ten years (RR=0.88, 95% CI: 0.77-1.00).
Conclusions: Our meta-analysis suggested that coffee consumption might be associated with a decreased risk of gastric cancer.
背景与目的：咖啡是世界上最为广泛的饮料之一，很多研究发现咖啡的饮用 量与胃癌之间存在一定的关系。本研究系统地分析了相关人群的风险以期得 到一个较为肯定的结论。实验方法：搜索2014 年7 月之前数据库Cochrane library, PubMed and Embase 中符合设定选入标准的相关研究。所有关于咖啡饮 用量和胃癌之间关系的流行病学研究均纳入研究，计算其相对危险度的95% 可信区间。结果：22 例研究（9 个队列研究，13 个病例对照研究）中，总共 有7,631 位病例，1,019,693 位健康对照。大量与少量咖啡饮用者的胃癌相对危 险度是0.94（95%可信区间为0.80-1.10），饮用者与非饮用者的胃癌相对危险 度是0.93（95%可信区间为0.88-0.99）。本研究按咖啡饮用的量分组。每天小 于一杯咖啡，1-2 杯咖啡和3-4 杯咖啡饮用量的人群与不饮咖啡的人群胃癌发 生的相对危险度分别是0.95（95%可信区间为0.84-1.08），0.92（95%可信区 间为0.82-1.03），0.88（95%可信区间为0.76-1.02）。这表明随着咖啡饮用量 的增加，胃癌的发生率降低。进而，将所有研究按照实验设计、性别、人 群、时间分组，在最近10 年的病例对照研究（相对危险度0.85，95%可信区 间为0.77-0.95）中，咖啡的饮用量与胃癌的发生呈负相关（相对危险度 0.88，95%可信区间为0.77-1.00）。结论：本meta 分析的结果提示咖啡的饮 用量与胃癌的发生率呈负相关。.