Evaluation of (−)-epicatechin metabolites as recovery biomarker of dietary flavan-3-ol intake

• Main Authors: Javier I. Ottaviani, Reedmond Fong, Jennifer Kimball, Jodi L. Ensunsa, Nicola Gray, Anna Vogiatzoglou, Abigail Britten, Debora Lucarelli, Robert Luben, Philip B. Grace, Deborah H. Mawson, Amy Tym, Antonia Wierzbicki, A. David Smith, Nicholas J. Wareham, Nita G. Forouhi, Kay-Tee Khaw, Hagen Schroeter, Gunter G. C. Kuhnle
• Format: Article
• Language: English
• Published: Nature Publishing Group 2019-09-01
• Series: Scientific Reports
• Online Access: https://doi.org/10.1038/s41598-019-49702-z

Abstract Data from dietary intervention studies suggest that intake of (−)-epicatechin mediates beneficial vascular effects in humans. However, population-based investigations are required to evaluate associations between habitual intake and health and these studies rely on accurate estimates of intake, which nutritional biomarkers can provide. Here, we evaluate a series of structurally related (−)-epicatechin metabolites (SREM), particularly (−)-epicatechin-3′-glucuronide, (−)-epicatechin-3′-sulfate and 3′-O-methyl-(−)-epicatechin-5-sulfate (SREMB), as flavan-3-ol and (−)-epicatechin intake. SREMB in urine proved to be a specific indicator of (−)-epicatechin intake, showing also a strong correlation with the amount of (−)-epicatechin ingested (R2: 0.86 (95% CI 0.8l; 0.92). The median recovery of (−)-epicatechin as SREMB in 24 h urine was 10% (IQR 7–13%) and we found SREMB in the majority of participants of EPIC Norfolk (83% of 24,341) with a mean concentration of 2.4 ± 3.2 µmol/L. Our results show that SREMB are suitable as biomarker of (−)-epicatechin intake. According to evaluation criteria from IARC and the Institute of Medicine, the results obtained support use of SREMB as a recovery biomarker to estimate actual intake of (−)-epicatechin.