16 Swedish subjects were given rye bran flakes containing 11, 22, or 44 mg total alkylresorcinols (AR) 3 times daily during week-long intervention period. Both plasma AR concentrations and urinary metabolites in 24-h samples showed a dose-response relation to increased AR intake, which strongly supports the hypothesis that ARs and their metabolites may be useful as biomarkers of whole grain wheat and rye intakes.