University of California, Davis, Sacramento, California 95616, USA.
Nutr Cancer. 2010;62(8):1036-43. doi: 10.1080/01635581.2010.492085.
The efficacy and safety of consuming high-dose isoflavone supplements for prostate cancer is not clear. A double-blind, placebo controlled, randomized trial was conducted in 53 men with prostate cancer enrolled in an active surveillance program. The treatment group consumed a supplement containing 450 mg genistein, 300 mg daidzein, and other isoflavones daily for 6 mo. Prostate-specific antigen (PSA) was measured in both groups at baseline, 3 mo, and 6 mo, and serum concentrations of genistein, daidzein, and equol were assessed at baseline and 6 mo in the treatment group. Following the completion of the 6-mo double-blind study, men were enrolled in a 6-mo open label trial with the same isoflavone-rich supplement, and PSA was measured at 3 and 6 mo. PSA concentrations did not change in either group after 6 mo or after 12 mo when the open-label study was included. The 6 mo serum concentrations of genistein and daidzein (39.85 and 45.59 μmol/l, respectively) were significantly greater than baseline values and substantially higher than levels previously reported in other studies. Equol levels did not change. Although high amounts of aglycone isoflavones may result in significantly elevated serum concentrations of genistein and daidzein, these dietary supplements alone did not lower PSA levels in men with low-volume prostate cancer.
高剂量异黄酮补充剂对前列腺癌的疗效和安全性尚不清楚。一项双盲、安慰剂对照、随机临床试验在 53 名参加主动监测计划的前列腺癌患者中进行。治疗组每天服用含有 450 毫克染料木黄酮、300 毫克大豆苷元和其他异黄酮的补充剂，持续 6 个月。两组患者在基线、3 个月和 6 个月时测量前列腺特异性抗原（PSA），并在治疗组的基线和 6 个月时测量染料木黄酮、大豆苷元和雌马酚的血清浓度。在完成 6 个月的双盲研究后，男性参加了为期 6 个月的开放标签试验，使用相同的富含异黄酮的补充剂，并在 3 个月和 6 个月时测量 PSA。6 个月或包括开放标签研究的 12 个月后，两组的 PSA 浓度均未发生变化。6 个月时血清中染料木黄酮和大豆苷元的浓度（分别为 39.85 和 45.59 μmol/L）明显高于基线值，远高于以前其他研究报告的水平。雌马酚水平没有变化。尽管大量的苷元异黄酮可能导致染料木黄酮和大豆苷元的血清浓度显著升高，但这些膳食补充剂单独使用并不能降低低体积前列腺癌患者的 PSA 水平。
