Biomarkers of isoflavone intake : validity at high intakes

摘要: Isoflavones are biologically active plant chemicals (phytoestrogens) which ordinarily present in human diets. There is considerable research interest their potential to prevent or treat several chronic diseases. Biomarkers can demonstrate compliance during dietary interventions and validate associations between intake of isoflavones health outcomes. The objectives this study were 24-hour urine collections, timed spot samples plasma as biomarkers isoflavone up 165mg/day. Healthy volunteers (20 women 11 men) consumed 55mg/d, 110mg/d 165mg/d soy placebo for seven consecutive days a randomised, double-blind, crossover study. Timed blood samples, (taken the afternoon, 5-7 hours after consuming supplement) urines obtained at baseline each intervention. Isoflavone content was assayed by liquid chromatography mass spectrometry. validated percentage PABA recovery. relationship daily urinary excretion was: y = 6.63132x ≡ x (y ÷ 6.63132) where μg/24h r 0.86; p < 0.001; n 109 from 31 concentration (3.3543x10)x 3.3543x10) μg/ml 0.61; 100 30 (2.0324x10)x 2.0324x10) 0.69; 143 It concluded that valid intakes A curvilinear defined a) dose bioavailability b) excretion. I, Lorna Jay Mackinnon, hereby certify thesis, approximately 24,000 words length, has been written me, it record work carried out me not submitted any previous application higher degree. Date: Signature Candidate: I admitted student September 2004 candidate degree MPhil 2004; University St Andrews 2006. fulfilled conditions Resolution Regulations appropriate qualified submit thesis Supervisor: In submitting understand am giving permission be made available use accordance with regulations Library time being force, subject copyright vested affected thereby. also title abstract will published, copy may supplied bona fide library worker.