Potential risks and benefits of phytoestrogen-rich diets
Potential risks and benefits of phytoestrogen-rich diets
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DOI：
10.1024/0300-9831.73.2.120
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发表时间：
2003-03-01
影响因子：
2.3
通讯作者：
Cassidy, A
中科院分区：
文献类型：
--
作者：
Cassidy, A
在过去的十年里，人们对植物中存在的生物活性化合物的生理作用的兴趣急剧增加。与人类健康有关的特别感兴趣的是一类被称为植物雌激素的化合物，它包含几类非甾体雌激素，包括广泛分布在植物界的异黄酮类和木脂素。来自动物和体外研究的数据提供了合理的机制来解释植物雌激素如何影响激素依赖状态，但是尽管富含这些雌激素模拟物的饮食的临床应用还处于起步阶段，来自初步研究的数据表明对健康具有重要的潜在有益作用。植物雌激素在化学结构上与哺乳动物雌激素惊人地相似。雌激素，并与雌激素受体(ER)结合，偏爱最近描述的ERβ。这表明这些化合物可能会产生组织特异性效应。许多其他独立于内质网的生物效应(如抗氧化能力、抗增殖和抗血管生成作用)被归因于这些化合物。植物雌激素在人体内是否具有生物活性，无论是激素还是非激素，都是一个有争议的问题，目前关于人体暴露的数据很少。关于饮食中植物雌激素的吸收和代谢的现有数据大多是定性的；众所周知，饮食中的植物雌激素是由肠道细菌代谢的，在肝脏中吸收，结合在肝脏中，在血浆中循环，在尿中排泄。最近的研究定量研究了大豆异黄酮摄入后的变化--用纯化合物和稳定的同位素数据来补充最近大豆食品的药代动力学数据。到目前为止在人类身上进行的有限研究清楚地证实了大豆异黄酮可以发挥激素效应。这些效果可能有助于预防西方人群中观察到的许多常见疾病(如乳腺癌、前列腺癌、更年期症状、骨质疏松症)，这些疾病的饮食通常缺乏这些具有生物活性的天然化合物。然而，由于生物效应取决于许多因素，包括剂量、使用时间、蛋白质结合亲和力、个体代谢和内在雌激素状态，因此有必要进行进一步的临床研究，以确定这些化合物在特定人群中的潜在健康影响。然而，我们目前对接触这些化合物的年龄差异知之甚少，也几乎没有关于特定健康后果的最佳剂量的指导方针。
Interest in the physiological role of bioactive compounds present in plants has increased dramatically over the last decade. Of particular interest in relation to human health are the class of compounds known as the phytoestrogens, which embody several groups of non-steroidal oestrogens including isoflavones & lignans that are widely distributed within the plant kingdom. Data from animal and in vitro studies provide plausible mechanisms to explain how phytoestrogens may influence hormone dependent states, but although the clinical application of diets rich in these oestrogen mimics is in its infancy, data from preliminary studies suggest potential beneficial effects of importance to health.Phytoestrogens are strikingly similar in chemical structure to the mammalian oestrogen. oestradiol, and bind to oestrogen receptors (ER) with a preference for the more recently described ERbeta. This suggests that these compounds may exert tissue specific effects. Numerous other biological effects independent of the ER (e.g. antioxidant capacity, antiproliferative and antiangiogenic effects) have been ascribed to these compounds. Whether phytoestrogens have any biological activity in humans, either hormonal or non hormonal is a contentious issue and there is currently a paucity of data on human exposure.Much of the available data on the absorption and metabolism of dietary phytoestrogens is of a qualitative nature; it is known that dietary phytoestrogens are metabolised by intestinal bacteria, absorbed, conjugated in the liver, circulated in plasma and excreted in urine. Recent studies have addressed quantitatively what happens to isoflavones following ingestion - with pure compound and stable isotope data to compliment recent pharmacokinetic data for soy foods.The limited studies conducted so far in humans clearly confirm that soya isoflavones can exert hormonal effects. These effects may be of benefit in the prevention of many of the common diseases observed in Western populations (such as breast cancer, prostate cancer, menopausal symptoms, osteoporosis) where the diet is typically devoid of these biologically active naturally occurring compounds. However since biological effects are dependent on many factors including dose, duration of use, protein binding affinity, individual metabolism and intrinsic oestrogenic state, further clinical studies are necessary to determine the potential health effects of these compounds in specific population groups. However we currently know little about age related differences in exposure to these compounds and there are few guidelines on optimal dose for specific health outcomes.