title: Absorption of isoflavones in humans: effects of food matrix and processing.
abstract: If soy isoflavones are to be effective in preventing or treating a range of diseases, they must be bioavailable, and thus understanding factors which may alter their bioavailability needs to be elucidated. However, to date there is little information on whether the pharmacokinetic profile following ingestion of a defined dose is influenced by the food matrix in which the isoflavone is given or by the processing method used. Three different foods (cookies, chocolate bars and juice) were prepared, and their isoflavone contents were determined. We compared the urinary and serum concentrations of daidzein, genistein and equol following the consumption of three different foods, each of which contained 50 mg of isoflavones. After the technological processing of the different test foods, differences in aglycone levels were observed. The plasma levels of the isoflavone precursor daidzein were not altered by food matrix. Urinary daidzein recovery was similar for all three foods ingested with total urinary output of 33-34% of ingested dose. Peak genistein concentrations were attained in serum earlier following consumption of a liquid matrix rather than a solid matrix, although there was a lower total urinary recovery of genistein following ingestion of juice than that of the two other foods.
authors.affiliation: Department of Plant Food Sciences and Technology, CSIC, Instituto del Frio, José Anotonio Novais 10, Ciudad Universitaria, Madrid, Spain. soniapt@if.csic.es
authors.forename: Sonia
authors.initials: S
authors.lastname: de Pascual-Teresa
authors.forename: Jesper
authors.initials: J
authors.lastname: Hallund
authors.forename: Duncan
authors.initials: D
authors.lastname: Talbot
authors.forename: Joyce
authors.initials: J
authors.lastname: Schroot
authors.forename: Christine M
authors.initials: CM
authors.lastname: Williams
authors.forename: Susanne
authors.initials: S
authors.lastname: Bugel
authors.forename: Aedin
authors.initials: A
authors.lastname: Cassidy
mesh_terms: D000042:Absorption; D001628:Beverages; D001682:Biological Availability; D004063:Digestion; D060754:Equol; D005502:Food; D005504:Food Analysis; D005511:Food Handling; D019833:Genistein / Q000097:blood / Q000652:urine; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D008875:Middle Aged
chemical_list: C007610:4',7-dihydroxy-3,4-dihydroisoflavone; D007529:Isoflavones; D060754:Equol; C004742:daidzein; D019833:Genistein