Setchell Kenneth D R, Brown Nadine M, Lydeking-Olsen Eva
Clinical Mass Spectrometry, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, OH 45229, USA.
J Nutr. 2002 Dec;132(12):3577-84. doi: 10.1093/jn/132.12.3577.
Equol [7-hydroxy-3-(4'-hydroxyphenyl)-chroman] is a nonsteroidal estrogen of the isoflavone class. It is exclusively a product of intestinal bacterial metabolism of dietary isoflavones and it possesses estrogenic activity, having affinity for both estrogen receptors, ERalpha and ERbeta. Equol is superior to all other isoflavones in its antioxidant activity. It is the end product of the biotransformation of the phytoestrogen daidzein, one of the two main isoflavones found in abundance in soybeans and most soy foods. Once formed, it is relatively stable; however, equol is not produced in all healthy adults in response to dietary challenge with soy or daidzein. Several recent dietary intervention studies examining the health effects of soy isoflavones allude to the potential importance of equol by establishing that maximal clinical responses to soy protein diets are observed in people who are good "equol-producers." It is now apparent that there are two distinct subpopulations of people and that "bacterio-typing" individuals for their ability to make equol may hold the clue to the effectiveness of soy protein diets in the treatment or prevention of hormone-dependent conditions. In reviewing the history of equol, its biological properties, factors influencing its formation and clinical data, we propose a new paradigm. The clinical effectiveness of soy protein in cardiovascular, bone and menopausal health may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic isoflavone, equol. The failure to distinguish those subjects who are "equol-producers" from "nonequol producers" in previous clinical studies could plausibly explain the variance in reported data on the health benefits of soy.
雌马酚[7-羟基-3-(4'-羟基苯基)-苯并二氢吡喃]是异黄酮类的一种非甾体雌激素。它完全是膳食异黄酮经肠道细菌代谢的产物，具有雌激素活性，对雌激素受体ERα和ERβ均有亲和力。雌马酚的抗氧化活性优于所有其他异黄酮。它是植物雌激素大豆苷元生物转化的终产物，大豆苷元是大豆和大多数大豆食品中大量存在的两种主要异黄酮之一。一旦形成，它相对稳定；然而，并非所有健康成年人在接受大豆或大豆苷元的膳食挑战后都会产生雌马酚。最近几项研究大豆异黄酮健康影响的膳食干预研究暗示了雌马酚的潜在重要性，这些研究表明，在“雌马酚高产者”中观察到了对大豆蛋白饮食的最大临床反应。现在很明显，人群中有两个不同的亚群，根据个体产生雌马酚的能力进行“细菌分型”可能是大豆蛋白饮食在治疗或预防激素依赖性疾病中有效性的关键。在回顾雌马酚的历史、其生物学特性、影响其形成的因素和临床数据时，我们提出了一个新的范式。大豆蛋白在心血管、骨骼和更年期健康方面的临床有效性可能取决于将大豆异黄酮生物转化为更有效的雌激素异黄酮雌马酚的能力。在先前的临床研究中未能区分“雌马酚生产者”和“非雌马酚生产者”，这可能合理地解释了关于大豆健康益处的报告数据的差异。
