SOYBEAN DIET AND BREAST DENSITY

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 与许多亚洲国家一样，消费高水平大豆的人群与消费典型西方饮食的人群相比，卵巢激素水平较低，乳腺癌发病率较低，乳房X线摄影密度也较低。 我们发现，在绝经前妇女中，大豆喂养有利地降低了25-45%的卵巢激素。 我们建议测试的排版，消费大豆减少卵巢类固醇激素（雌二醇，雌酮，硫酸，孕酮），并导致相应的乳房密度的降低，这些效果可以实现与大豆饮食，不含孕酮。 目标1确定评估慢性大豆暴露的潜在不良影响。 将通过进行一项随机、双盲研究来检验该目标，该研究分为两组，每组100名绝经前妇女，乳腺组织致密性50%的绝经前妇女将被随机分配到每天服用不含大豆酮的豆浆（治疗）或牛奶（安慰剂）作为膳食补充剂，持续2年。 在这两组妇女中，将在饮食干预之前、期间和之后2年评估卵巢类固醇、激素和乳房密度的比较水平。降低乳腺密度有望通过两种机制降低乳腺癌风险，即，减少有癌症发展风险的目标组织的体积，并提高乳房X线照相术用于早期筛查检测的灵敏度。 我们的长期目标之一是确定大豆是否可以作为第二种乳腺癌的替代和补充预防措施。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Populations consuming high levels of soy, as in many Asian countries, have lower levels of ovarian hormones, lower rates of breast cancer, and reduced mammographic density than populations consuming typical Western diets. We found that soy feeding favorably lowered ovarian hormones by 25-45% in premenopausal women. We propose to test the typothesis that consumption of soya reduces ovarian steroid hormones (estradiol, estrone, sulfate, and progesterone) and results in a corresponding reduction in breast density and that these effects can be achieved with a soy diet that does not contain isoflavones. Aim 1 determines the assess potential adverse effects of chronic soy exposure. The aims will be tested by conducting a randomized, double-blind study, with two arms and 100 premenopausal women in each arm. Premenopausal women with 50% of dense breast tissue will randomly allocated to take soymilk without isoflavones (treatment) or cow milk (placebo) as dietary supplements daily for 2 years. The comparative levels of ovarian steroids, hormones and breast density will be assessed before, during and after 2 years of dietary interventions in these two groups of women. Reducing breast density can be expected to reduce breast cancer risk by two mechanisms, i.e., reducing the volume of target tissue at risk for cancer development and improving the sensitivity of mammography for early screening detection. One of our long-term objectives is to determine if soy can be an alternative and complementary preventive measure for a second breast cancer.