The effects of daily consumption of anthocyanins on bioavailability has remained unclear. In this study, we evaluated whether daily consumption affects the absorption rate of anthocyanins in rats when consumed during the active and sleep phase. Eighty rats were randomly divided into two groups. The first group consumed AIN-93G control diets, and the second group consumed AIN-93G diets containing 1% bilberry extract for 2 weeks. After 12 h fast, anthocyanins were not detected in plasma of rats. Bilberry extract (500 mg/kg body weight) was then orally administered at the beginning of the diurnal light period (ZT0, sleep phase) or at the end of the diurnal light period (ZT12, active phase). Blood concentrations of anthocyanins peaked 1 h after administration in both groups. Maximum blood concentration in rats that consumed bilberry extract daily (852 nM) was higher than that in control rats (630 nM) when the extract was administered at ZT0 but not at ZT12. Daily consumption of anthocyanins increases their absorption rate, but this effect is limited to the beginning of the sleep phase.
Keywords: anthocyanin; bilberry extract; bioavailability; daily consumption; diurnal rhythm.