title: Plasma alkylresorcinol concentrations correlate with whole grain wheat and rye intake and show moderate reproducibility over a 2- to 3-month period in free-living Swedish adults.
abstract: Plasma alkylresorcinols (AR) are useful as dietary biomarkers of wheat and rye whole grain (WG) during interventions but need to be validated in free-living populations. This study estimated the medium-term reproducibility and relative validity of plasma AR as biomarkers of WG and cereal fiber intake. Seventy-two Swedish adults kept 3-d weighed food records on 2 occasions 2-3 mo apart. Of these men and women, 51 provided a fasting blood sample at the end of each occasion. In addition, 18 participants provided 3 fasting and 3 nonfasting samples for 3 consecutive days on the first and second occasions, respectively. Dietary and blood variables did not differ between the 2 occasions. Nonfasting plasma total AR concentration [210 nmol/L (95% CI: 140, 314)] was higher than fasting [99 nmol/L (95% CI: 72, 137)] (P < 0.0001). Mean WG intake was 70 ± 61 g/d (41% from rye) and the intra-class correlation coefficient was 0.44 (95% CI: 0.26, 0.63) for total WG intake and 0.47 (95% CI: 0.27, 0.67) for the fasting plasma total AR concentration, suggesting moderate reproducibility. Fasting plasma total AR moderately correlated with WG rye + wheat (r(s) = 0.53; P < 0.001) and cereal fiber intake (r(s) = 0.32; P < 0.05) when using mean values from both occasions. This suggests that plasma AR concentration in fasting samples can be used as a biomarker of rye + wheat WG intake in free-living populations with a high and consistent WG intake.
authors.affiliation: Department of Food, Nutrition and Dietetics, Uppsala University, Uppsala, Sweden.
authors.forename: Agneta
authors.initials: A
authors.lastname: Andersson
authors.forename: Matti
authors.initials: M
authors.lastname: Marklund
authors.forename: Marina
authors.initials: M
authors.lastname: Diana
authors.forename: Rikard
authors.initials: R
authors.lastname: Landberg
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood* / Q000378:metabolism; D004043:Dietary Fiber; D005215:Fasting; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012118:Resorcinols / Q000097:blood* / Q000378:metabolism; D012434:Secale; D013997:Time Factors; D014908:Triticum; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004043:Dietary Fiber; D012118:Resorcinols