Wu A H, Ziegler R G, Nomura A M, West D W, Kolonel L N, Horn-Ross P L, Hoover R N, Pike M C
Department of Preventive Medicine, University of Southern California, Los Angeles 90033-0800, USA.
Am J Clin Nutr. 1998 Dec;68(6 Suppl):1437S-1443S. doi: 10.1093/ajcn/68.6.1437S.
Evidence from case-control studies suggests, although not entirely consistently, that soy intake may protect against breast cancer. The designs and findings of studies conducted in Asian women living in Japan, Singapore, China, and the United States are reviewed. Because of the considerably higher intake of soy by native Asians than by Asian Americans living in California and Hawaii, these studies investigated different segments of the dose-response relation between soy intake and breast cancer risk. Data are not sufficient to determine the amount or frequency of soy intake effective in protecting against breast cancer. Of concern is that soy intake may be homogeneously high in Asia, making it difficult to identify differences in breast cancer risk between high and moderate daily consumers. In studies conducted in Asian Americans, it is difficult to be certain that soy intake is not a marker of other factors related to Western lifestyle that are causally associated with risk of breast cancer. Additional studies assessing the role of soy and breast cancer are needed. These studies should assess intake of all food sources of soy, considering portion size as well as other dietary and nondietary factors that may confound the soy-breast cancer association. A better understanding of the mechanisms whereby soy intake may influence the risk of breast cancer is also needed. Dietary intervention studies with soy will provide information on the acute effects of soy on endogenous hormone concentrations. Cross-sectional and longitudinal studies are necessary to investigate the longer-term relations between hormone concentrations and soy intake in women.
病例对照研究的证据表明，大豆摄入量可能预防乳腺癌，不过这一结论并非完全一致。本文回顾了在日本、新加坡、中国以及美国生活的亚洲女性中开展的研究的设计与结果。由于亚洲本土居民的大豆摄入量远高于生活在加利福尼亚州和夏威夷的亚裔美国人，这些研究调查了大豆摄入量与乳腺癌风险之间剂量反应关系的不同部分。目前尚无足够数据确定预防乳腺癌的有效大豆摄入量或摄入频率。令人担忧的是，亚洲人的大豆摄入量可能普遍较高，因此难以确定每日大豆摄入量高的人群与中等摄入量人群在乳腺癌风险上的差异。在针对亚裔美国人开展的研究中，很难确定大豆摄入量不是与西方生活方式相关的其他因素的一个标志，而这些因素与乳腺癌风险存在因果关系。还需要开展更多评估大豆与乳腺癌关系的研究。这些研究应评估所有大豆食物来源的摄入量，同时考虑食物分量以及可能混淆大豆与乳腺癌关系的其他饮食和非饮食因素。还需要更好地了解大豆摄入量可能影响乳腺癌风险的机制。大豆饮食干预研究将提供大豆对体内激素浓度急性影响的信息。横断面研究和纵向研究对于调查女性激素浓度与大豆摄入量之间的长期关系很有必要。
