Determinants of plasma alkylresorcinol concentration in Danish post-menopausal women

Abstract

Alkylresorcinols (AR), a group of phenolic lipids present in the outer parts of wheat and rye grain kernels, have been suggested as biomarkers of whole-grain wheat and rye intake. In this study, we investigated potential determinants of plasma AR concentration in a free-living population. Non-fasting samples from post-menopausal women enrolled in the Danish Diet, Cancer and Health study (n = 360) were selected. Diet was assessed using a semi-quantitative food frequency questionnaires (FFQ) and the association between food items likely to contain AR and relevant non-dietary factors were studied by analysis of covariance models. The median AR concentration was 78 nmol/l (interquartile range = 106.9 nmol/l). Intake of rye bread, identified as the main determinant, was associated with 87% higher plasma total AR concentration per 100 g of bread (95% confidence interval = 46-139%). About 8-12% of the total variation (depending on the AR homologue) in plasma AR concentration was explained by the selected dietary variables. At a nutrient level, total dietary fiber and cereal fiber were significantly associated with plasma total AR concentration (P = 0.05), but only ≈2% of the total plasma AR concentration was explained by the dietary fiber or cereal fiber intake. In the studied population, AR plasma concentration was mainly affected by rye bread intake among investigated determinants.