The Whiteley-Martin Research Centre, The Discipline of Surgery, Sydney Medical School, Nepean Hospital, The University of Sydney, Level 3, Clinical Building, Penrith, NSW, 2751, Australia.
Eur J Nutr. 2016 Feb;55(1):63-73. doi: 10.1007/s00394-014-0824-7. Epub 2014 Dec 30.
Evidence suggests that soy foods have chemoprotective properties that may reduce the risk of certain cancers such as breast and prostate cancer. However, data involving gastrointestinal (GI) have been limited, and the evidence remains controversial. This study aims to determine the potential relationship between dietary soy intake and GI cancer risk with an evaluation of the effects of isoflavone as an active soy constituent.
Relevant studies were identified after literature search via electronic databases through May 2014. Subgroup analysis for isoflavone intake (studies n = 10) was performed. Covariants including gender types, anatomical subsites and preparation methods were also evaluated. Pooled adjusted odds ratios (ORs) comparing highest and lowest categories of dietary pattern scores were calculated using a random effects model.
Twenty-two case-control and 18 cohort studies were included for meta-analysis, which contained a total of 633,476 participants and 13,639 GI cancer cases. The combined OR was calculated as 0.93 (95% CI 0.87-0.99; p value heterogeneity = 0.01), showing only a slight decrease in risk, the association was stronger for colon cancer (OR 0.92; 95% CI 0.96-0.99; p value heterogeneity = 0.163) and colorectal cancer (CRC) (OR 0.92; 95% CI 0.87-0.97; p value heterogeneity = 0.3). Subgroup analysis for isoflavone intake showed a statistically significant risk reduction with a risk estimate of 0.73 (95% CI 0.59-0.92; p value heterogeneity = 0), and particularly for CRC (OR 0.76; 95% CI 0.59-0.98; p value heterogeneity = 0).
This study provides evidence that soy intake as a food group is only associated with a small reduction in GI cancer risk. Separate analysis for dietary isoflavone intakes suggests a stronger inverse association.
有证据表明，大豆食品具有化学预防特性，可能降低某些癌症的风险，如乳腺癌和前列腺癌。然而，涉及胃肠道（GI）的资料有限，而且证据仍然存在争议。本研究旨在确定饮食中大豆摄入量与 GI 癌症风险之间的潜在关系，并评估作为大豆活性成分的异黄酮的作用。
通过电子数据库检索文献，于 2014 年 5 月后确定相关研究。对异黄酮摄入量（研究 n = 10）进行亚组分析。还评估了包括性别类型、解剖部位和制备方法在内的协变量。使用随机效应模型计算比较饮食模式评分最高和最低类别的合并调整比值比（OR）。
22 项病例对照和 18 项队列研究被纳入荟萃分析，共纳入 633476 名参与者和 13639 例 GI 癌症病例。合并 OR 计算为 0.93（95%CI 0.87-0.99；p 值异质性=0.01），表明风险略有下降，这种关联在结肠癌（OR 0.92；95%CI 0.96-0.99；p 值异质性=0.163）和结直肠癌（CRC）（OR 0.92；95%CI 0.87-0.97；p 值异质性=0.3）中更强。异黄酮摄入量的亚组分析显示，风险降低具有统计学意义，风险估计值为 0.73（95%CI 0.59-0.92；p 值异质性=0），特别是在 CRC（OR 0.76；95%CI 0.59-0.98；p 值异质性=0）中。
本研究提供的证据表明，大豆作为一种食物组的摄入量仅与 GI 癌症风险的微小降低相关。对饮食异黄酮摄入量的单独分析表明，两者之间存在更强的反比关系。
