Soy contains many bioactive phytochemicals, such as isoflavones, which have the effect of preventing many cancers. Some studies have shown the beneficial effect of soy-based food and isoflavone intake on gastric cancer (GC), while others claimed no effect. Therefore, whether the beneficial effect of soy-based food is related to its fermentation or whether its protective effect comes from isoflavones still remains inconclusive. Our aim was to investigate the relationship between total soybean, fermented soybean, non-fermented soybean and isoflavone intake, and the risk of GC. Ten cohort studies and 21 case–control studies involving 916 354 participants were included. The association between soy-based food and isoflavone intake and the risk of GC was calculated with the pooled relative risks (RRs) for the highest versus lowest intake categories. The results showed that isoflavone intake might be a protective factor to GC, but the result was not statistically significant (RR = 0.92; 95% CI: 0.79–1.07). However, total soybean intake could significantly decrease the risk of GC by 36% (RR = 0.64; 95% CI: 0.51–0.80), which might be credited to non-fermented soybean products (RR = 0.79; 95% CI: 0.71–0.87). In contrast, high intake of fermented soybean products could increase the risk of GC (RR = 1.19; 95% CI: 1.02–1.38). High intake of total soybean and non-fermented soybean products could reduce the risk of GC, and high intake of fermented soybean products could increase the risk, which indicated that the beneficial effect of soy-based food might be related to its non-fermentation. However, high intake of isoflavones may not be associated with the incidence of GC. © 2021 Society of Chemical Industry.

中文翻译：

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大豆食品和大豆异黄酮摄入量与胃癌风险之间的关联：系统评价和荟萃分析


大豆中含有多种生物活性植物化学物质，如异黄酮，具有预防多种癌症的作用。一些研究表明，大豆食品和异黄酮摄入对胃癌 (GC) 有益，而另一些研究则声称没有效果。因此，大豆食品的有益作用是否与其发酵有关，或者其保护作用是否来自异黄酮，仍然没有定论。我们的目的是调查大豆总量、发酵大豆、非发酵大豆和异黄酮摄入量与GC风险之间的关系。其中包括 10 项队列研究和 21 项病例对照研究，涉及 916 354 名参与者。大豆食品和异黄酮摄入量与GC风险之间的关联是通过最高与最低摄入量类别的汇总相对风险（RR）来计算的。结果显示，异黄酮摄入可能是GC的保护因素，但结果不具有统计学意义（RR=0.92；95%CI：0.79-1.07）。然而，大豆总摄入量可显着降低 GC 风险 36%（RR = 0.64；95% CI：0.51–0.80），这可能归功于非发酵豆制品（RR = 0.79；95% CI：0.71– 0.87）。相反，大量摄入发酵豆制品会增加胃癌风险（RR = 1.19；95% CI：1.02–1.38）。高摄入全大豆和非发酵豆制品可降低GC风险，高摄入发酵豆制品可增加GC风险，这表明豆类食品的有益作用可能与其非发酵有关。然而，大量摄入异黄酮可能与GC的发生无关。 © 2021 化学工业学会。