title: Plasma alkylresorcinols reflect important whole-grain components of a healthy Nordic diet.
abstract: Biomarkers of dietary intake can be important tools in nutrition research. Our aim was to assess whether plasma alkylresorcinol (AR) and β-carotene concentrations could be used as dietary biomarkers for whole-grain, fruits and vegetables in a healthy Nordic diet (ND). Participants (n = 166), 30-65 y with a body mass index of 27-40 kg/m(2) and two more features of metabolic syndrome (International Diabetes Federation definition, slightly modified), were recruited through six centers in the Nordic countries and randomly assigned to an ND or control diet for 18 or 24 wk, depending on study center. Plasma AR and β-carotene were analyzed and nutrient intake calculated from 4-d food records. Median fiber intake increased in the ND group from 2.5 g/MJ at baseline to 4.1 g/MJ (P < 0.001) at end point (week 18 or 24), and median (IQR) fasting plasma total AR concentration increased from 73 (88) to 106 (108) nmol/L, or 45%, from baseline to end point (P < 0.001). The AR concentration was significantly higher in the ND group (P < 0.001) than in the control group at end point. β-Carotene intake tended to increase in the ND group (P = 0.07), but the plasma β-carotene concentration did not change significantly throughout the study and did not differ between the groups at follow-up. In conclusion, an ND resulted in higher dietary fiber intake and increased plasma total AR concentration compared with the control diet, showing that the total AR concentration might be a valid biomarker for an ND in which whole-grain wheat and rye are important components. No significant difference in plasma β-carotene concentrations was observed between the ND and control groups, suggesting that β-carotene may not be a sensitive enough biomarker of the ND.
authors.affiliation: Unit for Nutrition Research, Landspitali, The National University of Iceland, Faculty of Food Science and Nutrition and School of Health Sciences, University of Iceland, Reykjavík, Iceland.
authors.forename: Ola Kally
authors.initials: OK
authors.lastname: Magnusdottir
authors.forename: Rikard
authors.initials: R
authors.lastname: Landberg
authors.forename: Ingibjorg
authors.initials: I
authors.lastname: Gunnarsdottir
authors.forename: Lieselotte
authors.initials: L
authors.lastname: Cloetens
authors.forename: Björn
authors.initials: B
authors.lastname: Åkesson
authors.forename: Gunilla
authors.initials: G
authors.lastname: Önning
authors.forename: Svandis Erna
authors.initials: SE
authors.lastname: Jonsdottir
authors.forename: Fredrik
authors.initials: F
authors.lastname: Rosqvist
authors.forename: Ursula
authors.initials: U
authors.lastname: Schwab
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Herzig
authors.forename: Markku J
authors.initials: MJ
authors.lastname: Savolainen
authors.forename: Lea
authors.initials: L
authors.lastname: Brader
authors.forename: Kjeld
authors.initials: K
authors.lastname: Hermansen
authors.forename: Marjukka
authors.initials: M
authors.lastname: Kolehmainen
authors.forename: Kaisa
authors.initials: K
authors.lastname: Poutanen
authors.forename: Matti
authors.initials: M
authors.lastname: Uusitupa
authors.forename: Inga
authors.initials: I
authors.lastname: Thorsdottir
authors.forename: Ulf
authors.initials: U
authors.lastname: Risérus
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001823:Body Composition; D015992:Body Mass Index; D004032:Diet; D004043:Dietary Fiber / Q000008:administration & dosage*; D002523:Edible Grain / Q000737:chemistry*; D002149:Energy Intake; D005215:Fasting; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood; D008875:Middle Aged; D015596:Nutrition Assessment; D012044:Regression Analysis; D012118:Resorcinols / Q000097:blood*; D014675:Vegetables; D019207:beta Carotene / Q000097:blood*
chemical_list: D015415:Biomarkers; D004043:Dietary Fiber; D012118:Resorcinols; D019207:beta Carotene