Messina Mark, McCaskill-Stevens Worta, Lampe Johanna W
Department of Nutrition, School of Public Health, Loma Linda University, Loma Linda, CA, USA.
J Natl Cancer Inst. 2006 Sep 20;98(18):1275-84. doi: 10.1093/jnci/djj356.
The impact of soyfood intake on breast cancer risk has been investigated extensively. Much of this focus can be attributed to the soybean being a dietary source that is uniquely rich in isoflavones. The chemical structure of isoflavones is similar to that of estrogen, and isoflavones bind to both estrogen receptors (ER alpha and ER beta) (although they preferentially bind to and activate ER beta) and exert estrogen-like effects under some experimental conditions. Isoflavones also possess nonhormonal properties that are associated with the inhibition of cancer cell growth. Thus, there are several possible mechanisms by which soy may reduce the risk of breast cancer. However, the role of isoflavones in breast cancer has become controversial because, in contrast to the possible beneficial effects, some data from in vitro and animal studies suggest that isoflavones, especially genistein, the aglycone of the main soybean isoflavone genistin, may stimulate the growth of estrogen-sensitive tumors. Limited human data directly address the tumor-promoting effects of isoflavones and soy. Because the use of soyfoods and isoflavone supplements is increasing, it is important from a public health perspective to understand the impact of these products on breast cancer risk in women at high risk of the disease and on the survival of breast cancer patients. To this end, a workshop was held in November 2005 to review the existing literature and to make research recommendations. This paper summarizes the workshop findings and recommendations. The primary research recommendation is that the impact of isoflavones on breast tissue needs to be evaluated at the cellular level in women at high risk for breast cancer.
大豆食品摄入量对乳腺癌风险的影响已得到广泛研究。这种关注很大程度上可归因于大豆是一种独特富含异黄酮的膳食来源。异黄酮的化学结构与雌激素相似，它能与两种雌激素受体（雌激素受体α和雌激素受体β）结合（尽管它优先结合并激活雌激素受体β），并在某些实验条件下发挥类似雌激素的作用。异黄酮还具有与抑制癌细胞生长相关的非激素特性。因此，大豆可能通过多种可能的机制降低乳腺癌风险。然而，异黄酮在乳腺癌中的作用已变得具有争议性，因为与可能的有益作用相反，一些体外和动物研究数据表明，异黄酮，尤其是染料木黄酮（主要大豆异黄酮染料木苷的苷元），可能刺激雌激素敏感性肿瘤的生长。有限的人体数据直接涉及异黄酮和大豆的促肿瘤作用。由于大豆食品和异黄酮补充剂的使用正在增加，从公共卫生角度了解这些产品对乳腺癌高危女性的乳腺癌风险以及乳腺癌患者生存的影响非常重要。为此，2005年11月举办了一次研讨会，以回顾现有文献并提出研究建议。本文总结了研讨会的结果和建议。主要研究建议是，需要在乳腺癌高危女性的细胞水平上评估异黄酮对乳腺组织的影响。
