Laboratory of Microbial Ecology and Technology, Faculty of Bioscience Engineering and the Laboratory of Experimental Cancer Research, Department of Experimental Cancer Research, Radiotherapy and Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
Am J Clin Nutr. 2010 Apr;91(4):976-84. doi: 10.3945/ajcn.2009.28854. Epub 2010 Feb 17.
Despite decades of research on the relation between soy and breast cancer, questions regarding the absorption, metabolism, and distribution of isoflavones in breast tissue largely remain unanswered.
We evaluated the potential health effects of isoflavone consumption on normal breast tissue; isoflavone concentrations, metabolites, and biodistribution were investigated and compared with 17beta-estradiol exposure.
In this dietary intervention study, healthy women were randomly allocated to a soy milk (n = 11; 16.98-mg genistein and 5.40-mg daidzein aglycone equivalents per dose), soy supplement (n = 10; 5.27-mg genistein and 17.56-mg daidzein aglycone equivalents per dose), or control (n = 10) group. After a run-in period > or = 4 d, 3 doses of soy milk or soy supplements were taken daily for 5 d before an esthetic breast reduction. Blood and breast biopsies were collected during surgery and analyzed with liquid chromatography-tandem mass spectrometry.
After soy administration, genistein and total daidzein concentrations, which were expressed as aglycone equivalents, ranged from 135.1 to 2831 nmol/L and 105.1 to 1397 nmol/L, respectively, in hydrolyzed serum and from 92.33 to 493.8 pmol/g and 22.15 to 770.8 pmol/g, respectively, in hydrolyzed breast tissue. The major metabolites identified in nonhydrolyzed samples were genistein-7-O-glucuronide and daidzein-7-O-glucuronide, with an overall glucuronidation of 98%. Total isoflavones showed a breast adipose/glandular tissue distribution of 40:60, and their mean (+/-SEM) derived 17beta-estradiol equivalents toward estrogen receptor beta were 21 +/- 4-fold and 40 +/- 10-fold higher than the 17beta-estradiol concentrations in adipose (0.283 +/- 0.089 pmol/g, P < 0.001) and glandular (0.246 +/- 0.091 pmol/g, P = 0.001) fractions, respectively.
After intake of soy milk and soy supplements, isoflavones reach exposure levels in breast tissue at which potential health effects may occur.
尽管几十年来人们一直在研究大豆与乳腺癌之间的关系，但有关大豆异黄酮在乳腺组织中的吸收、代谢和分布问题仍未得到解答。
评估大豆异黄酮摄入对正常乳腺组织的潜在健康影响；比较 17β-雌二醇暴露，对大豆异黄酮浓度、代谢物和分布进行了调查。
在这项饮食干预研究中，健康女性被随机分配到豆浆组（n = 11；每剂量 16.98mg 染料木黄酮和 5.40mg 大豆苷元糖苷元）、大豆补充剂组（n = 10；每剂量 5.27mg 染料木黄酮和 17.56mg 大豆苷元糖苷元）或对照组（n = 10）。在>或= 4d 的引入期后，每天服用 3 次豆浆或大豆补充剂，连续 5 天，然后进行美容乳房缩小术。在手术过程中收集血液和乳房活检，并通过液相色谱-串联质谱法进行分析。
大豆给药后，血清水解物中染料木黄酮和总大豆苷元浓度分别为 135.1 至 2831 nmol/L 和 105.1 至 1397 nmol/L，乳腺组织水解物中分别为 92.33 至 493.8 pmol/g 和 22.15 至 770.8 pmol/g。非水解样本中鉴定的主要代谢产物为染料木黄酮-7-O-葡糖苷酸和大豆苷元-7-O-葡糖苷酸，总体葡糖苷酸化率为 98%。大豆异黄酮在乳腺脂肪/腺体组织中的分布为 40:60，其对雌激素受体β的平均（+/-SEM）雌二醇当量分别比脂肪（0.283 +/- 0.089 pmol/g，P < 0.001）和腺体（0.246 +/- 0.091 pmol/g，P = 0.001）中雌二醇浓度高 21 +/- 4 倍和 40 +/- 10 倍。
摄入豆浆和大豆补充剂后，大豆异黄酮在乳腺组织中的暴露水平达到可能产生潜在健康影响的水平。
