title: Comparison of plasma alkylresorcinols (AR) and urinary AR metabolites as biomarkers of compliance in a short-term, whole-grain intervention study.
abstract: OBJECTIVE
  Alkylresorcinols (AR) are phenolic lipids present in the bran of wheat and rye. Plasma AR and their urinary metabolites may be suitable biomarkers of whole-grain (WG) wheat and rye consumption. The objective of this study was to examine plasma AR and urinary AR metabolites in response to WG wheat consumption.
  
  
  METHODS
  In a randomized crossover study, 19 subjects (10 males, 9 females; BMI 22.0 kg/m(2); age 26 years) incorporated either 3 servings (48 g) or 6 servings (96 g) of WG wheat daily into their regular diet for 1 week. Subjects completed a 2-week washout period, abstaining from all WG consumption, before each intervention. Fasting blood and 24-h urine were collected before and after each intervention. Plasma AR homologues (C19:0, C21:0, C23:0) were quantified by GC-MS after diethyl ether and solid phase extraction and derivatization. Urinary AR metabolites [3,5-dihydroxybenzoic acid and 3-(3,5-dihydroxyphenyl)-propanoic acid] were determined using HPLC with electrochemical detection after enzymatic deconjugation and ethyl acetate extraction.
  
  
  RESULTS
  Urinary total AR metabolites were significantly higher after 6 compared with 3 servings of WG wheat (56 vs. 32 μmol/day, P < 0.001). This dose-response relationship was independent of age, sex, energy intake, and baseline urinary AR metabolite concentration. Plasma total AR tended to be higher after 6 compared with 3 servings of WG wheat (103.0 vs. 86.9 nmol/L), but this difference was not significant (P = 0.42).
  
  
  CONCLUSIONS
  The results suggest that urinary AR metabolites from 24-h urine collections may be useful as biomarkers of compliance in intervention studies of WG wheat.
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA. nicola.mckeown@tufts.edu.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA. nicola.mckeown@tufts.edu.
authors.forename: Nicola M
authors.initials: NM
authors.lastname: McKeown
authors.affiliation: Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden.
authors.forename: Matti
authors.initials: M
authors.lastname: Marklund
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.
authors.forename: Jiantao
authors.initials: J
authors.lastname: Ma
authors.affiliation: Food and Nutritional Sciences, Department of Life Science Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Alastair B
authors.initials: AB
authors.lastname: Ross
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Alice H
authors.initials: AH
authors.lastname: Lichtenstein
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.
authors.forename: Kara A
authors.initials: KA
authors.lastname: Livingston
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Jacques
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Rasmussen
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Blumberg
authors.affiliation: Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA, 02111, USA.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
authors.forename: C-Y Oliver
authors.initials: CY
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood* / Q000652:urine*; D015992:Body Mass Index; D018592:Cross-Over Studies; D004032:Diet; D004043:Dietary Fiber / Q000008:administration & dosage; D005260:Female; D006801:Humans; D062385:Hydroxybenzoates / Q000652:urine; D008297:Male; D010349:Patient Compliance; D010666:Phenylpropionates / Q000652:urine; D012118:Resorcinols / Q000737:chemistry* / Q000652:urine; D012434:Secale; D014908:Triticum; D000067348:Whole Grains; D055815:Young Adult
chemical_list: C532605:3-(3,5-dihydroxyphenyl)-1-propanoic acid; D015415:Biomarkers; D004043:Dietary Fiber; D062385:Hydroxybenzoates; D010666:Phenylpropionates; D012118:Resorcinols; C076950:alpha-resorcylic acid
keywords: Alkylresorcinols; Biomarkers; Whole grain; Whole wheat