Journal Article

Comparison of plasma alkylresorcinols (AR) and urinary AR metabolites as biomarkers of compliance in a short-term, whole-grain intervention study

McKeown, Nicola M., Ross, Alastair B., Ma, Jiantao, Blumberg, Jeffrey B., Marklund, Matti, Jacques, Paul F., Rasmussen, Helen M., Livingston, Kara A., Lichtenstein, Alice H., Chen, C.-Y. Oliver

2016

Overview

Purpose 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). Conclusion 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.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Adolescent / Adult / Alkylresorcinols / Biomarkers / Biomarkers - blood / Biomarkers - urine / blood / Body Mass Index / Chemistry / Chemistry and Materials Science / compliance / Cross-Over Studies / derivatization / Diet / Dietary Fiber - administration & dosage / dose response / electrochemistry / energy intake / ethyl acetate / ethyl ether / fasting / Female / females / gas chromatography-mass spectrometry / high performance liquid chromatography / Humans / Hydroxybenzoates - urine / lipids / Male / males / metabolites / Nutrition / Original Contribution / Patient Compliance / Phenylpropionates - urine / Resorcinols - chemistry / Resorcinols - urine / rye / Secale / solid phase extraction / Triticum / urine / wheat / wheat bran / Whole grain / whole grain foods / Whole Grains / Whole wheat / Young Adult