SOYBEAN DIET AND BREAST DENSITY

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。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。我们建议测试的假设，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。 目的1确定饮食中添加无胆固醇大豆对卵巢激素水平和乳腺密度的影响。目的2评估这种干预的安全性。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，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。在两组的饮食干预之前、期间和之后2年，将评估卵巢类固醇、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。长期目标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 hypothesis 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 effects of a diet supplemented with isoflavone-free soy on ovarian hormone levels and breast density. Aim 2 assesses the safety of this intervention. 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 be 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 both groups. 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. A long-term objective is to determine if soy can be an alternative and complementary preventive measure for a second breast cancer.