Diagnostic performance of urinary resveratrol metabolites as a biomarker of moderate wine consumption.

BACKGROUND Nutritional biomarkers may be better measures of dietary exposure than self-reported dietary data. We evaluated resveratrol metabolites, potential biomarkers of wine consumption, in humans after moderate consumption of sparkling, white, or red wines. METHODS We performed 2 randomized, crossover trials and a cohort study. In the first study, 10 healthy men consumed 30 g of ethanol/day as sparkling wine or gin for 28 days. In the second trial, 10 healthy women consumed 20 g of ethanol/day as white or red wine for 28 days. We also evaluated 52 participants in a study on the effects of a Mediterranean diet on primary prevention of cardiovascular disease (the PREDIMED Study). We used liquid chromatography-tandem mass spectrometry to analyze urinary total resveratrol metabolites (TRMs) and predictive values and ROC curve analyses to assess the diagnostic accuracy. RESULTS We observed significant increases in TRMs [72.4 (95% confidence interval, 48.5-96.2; P = 0.005), 211.5 (166.6-256.3; P = 0.005), and 560.5 nmol/g creatinine (244.9-876.1; P = 0.005)] after consumption of sparkling, white, or red wine, respectively, but no changes after the washout or gin periods. In the cohort study, the reported daily dose of wine consumption correlated directly with TRMs (r = 0.654; P < 0.001). Using a cutoff of 90 nmol/g, we were able to use TRMs to differentiate wine consumers from abstainers with a sensitivity of 72% (60%-84%); and a specificity of 94% (87%-100%). CONCLUSIONS Resveratrol metabolites in urine may be useful biomarkers of wine intake in epidemiologic and intervention studies.