Daidzein Is a More Bioavailable Soymilk Isoflavone than Is Genistein in Adult Women

摘要: Soybean isoflavones are proposed to be anticarcinogenic, but their effective doses have not been established. To study the bioavailability of soybean for humans, 12 young adult women received single 0.7, 1.3 and 2.0 mg isoflavones/kg body wt in milk as part a liquid diet. Plasma, urine fecal were measured by reverse-phase HPLC. Average 24-h urinary recoveries daidzein genistein approximately 21% 9%, respectively, at all three doses. Urinary recovery was significantly greater than that (P < 0.001). Total excretion only 1-2% ingested amount. Plasma total isoflavone concentration increased 4.4 +/- 2.5 mumol/L 6.5 h after dose mg/kg. The plasma concentrations genisten equal. Twenty-four hours dosing, both nearly nil. Although seem 85% degraded intestine, bioavailability, especially daidzein, may sufficient exert some health-protective effects.