Nielsen Inge Lise Finné, Williamson Gary
Nutrient Bioavailability Group, Nestle Research Center, Lausanne, Switzerland.
Nutr Cancer. 2007;57(1):1-10. doi: 10.1080/01635580701267677.
Soy isoflavones have anticarcinogenic, antioxidant, and antiatherosclerotic activities. They also interact with the estrogen receptor, which makes them weak or moderate phytoestrogens. Because of their bioactivity, isoflavone bioavailability has been extensively studied in humans. This review summarizes data from intervention studies in humans, focusing on the factors that affect bioavailability. Summarizing data from 16 studies shows that the maximum concentration in plasma normalized to a constant dose of genistin is approximately 1.6 times that of genistein, and daidzin is approximately 1.8-fold higher than daidzein, whereas the half-life is not significantly different for aglycone and glucoside. There is a wide variation in the reported percentage urinary excretion that is not dependent on dose. Bioavailability is increased by a rapid gut transit time and by low fecal digestion rates and is decreased by a fiber-rich diet. There is no difference in bioavailability between pre- and postmenopausal women. The daily ingestion of soymilk for 1 wk does not affect bioavailability, but daily ingestion for a month increases excretion of equol in women. The factors or habitual diet characteristics that influence equol production are not clear, but equol production is limited with an immature flora. There is no consensus on which source of isoflavones results in the highest isoflavone bioavailability, and published studies present different results, although bioavailability is affected by whether the dose is given as food or drink. In conclusion, it is important to consider the factors affecting bioavailability of isoflavones when designing intervention studies.
大豆异黄酮具有抗癌、抗氧化和抗动脉粥样硬化活性。它们还与雌激素受体相互作用，这使它们成为弱或中等强度的植物雌激素。由于其生物活性，异黄酮的生物利用度已在人体中得到广泛研究。本综述总结了人体干预研究的数据，重点关注影响生物利用度的因素。总结16项研究的数据表明，以恒定剂量的染料木苷标准化后的血浆最大浓度约为染料木素的1.6倍，大豆苷约比黄豆苷元高1.8倍，而苷元和糖苷的半衰期无显著差异。报告的尿排泄百分比差异很大，且不依赖于剂量。快速的肠道转运时间和低的粪便消化率可提高生物利用度，而富含纤维的饮食则会降低生物利用度。绝经前和绝经后女性的生物利用度没有差异。连续1周每天摄入豆浆不会影响生物利用度，但连续1个月每天摄入会增加女性中雌马酚的排泄。影响雌马酚产生的因素或习惯性饮食特征尚不清楚，但未成熟的菌群会限制雌马酚的产生。关于哪种异黄酮来源导致最高的异黄酮生物利用度尚无共识，尽管生物利用度受剂量是以食物还是饮料形式给予的影响，但已发表的研究呈现出不同的结果。总之，在设计干预研究时，考虑影响异黄酮生物利用度的因素很重要。
