title: Urinary excretion of 13 dietary flavonoids and phenolic acids in free-living healthy subjects - variability and possible use as biomarkers of polyphenol intake.
abstract: OBJECTIVE
  Estimation of dietary intake of polyphenols is difficult, due to limited availability of food composition data and bias inherent to dietary assessment methods. The aim of the present study was to evaluate whether we could detect polyphenols and their metabolites in a spot urine sample in a free-living human population and whether it was related to those observed in 24-h urine samples, for potential use as a biomarkers of polyphenol intake.
  
  
  METHODS
  Four 24-h urine samples and two spot urine samples were collected from 154 participants of the SU.VI.MAX cohort (a randomized primary-prevention trial evaluating the effect of daily antioxidant supplementation on chronic diseases) in two separate studies over, respectively, a 7- and 2-day periods. Thirteen polyphenols and metabolites (chlorogenic acid (CGA), caffeic acid (CA), m-coumaric acid (mCOU), gallic acid (GA), 4-O-methylgallic acid (MeGA), quercetin (Q), isorhamnetin (MeQ), kaempferol (K), hesperetin (HESP), naringenin (NAR), phloretin (PHLOR), enterolactone (ENL) and enterodiol (END) were measured using HPLC-ESI-MS-MS.
  
  
  RESULTS
  Correlations between the urinary excretion levels were observed. The most significant were explained by metabolic filiations (CGA/CA, CA/mCOU, GA/MeGA, Q/MeQ, NAR/PHLOR, ENL/END) or co-occurrence in a same food source (NAR/HESP). Concentrations in spot samples correlated with those in 24-h urine sample (P<0.02, except for CA and for MeQ). Intra-individual variations were smaller than inter-individual variations for all polyphenols (P<0.01) except for MeGA and for PHLOR.
  
  
  CONCLUSIONS
  These results show that these polyphenols and metabolites are useful biomarkers for polyphenol intake.
authors.affiliation: U557 Inserm, U1125 Inra, Cnam, Paris 13/CRNH I-d-F, 74 rue Marcel Cachin, Bobigny, France.
authors.forename: L I
authors.initials: LI
authors.lastname: Mennen
authors.forename: D
authors.initials: D
authors.lastname: Sapinho
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: P
authors.initials: P
authors.lastname: Galan
authors.forename: S
authors.initials: S
authors.lastname: Hercberg
authors.forename: A
authors.initials: A
authors.lastname: Scalbert
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D004032:Diet; D004311:Double-Blind Method; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage / Q000378:metabolism / Q000652:urine*; D006801:Humans; D062385:Hydroxybenzoates / Q000652:urine*; D008297:Male; D008875:Middle Aged; D010636:Phenols / Q000008:administration & dosage* / Q000378:metabolism / Q000652:urine; D059808:Polyphenols
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D005419:Flavonoids; D062385:Hydroxybenzoates; D010636:Phenols; D059808:Polyphenols; C017616:phenolic acid