Absorption and metabolism of anthocyanins: Potential health effects

This manuscript reviews literature on anthocyanins in foods and their metabolism and absorption and possible relationships to human health. Of the various classes of flavonoids, the potential dietary intake of anthocyanins is perhaps the greatest (100+ mg/day). The content in fruits varies considerably between 0.25 to 700 mg/100 g fresh weight. Not only does the concentration vary, the individual specific anthocyanins present also are quite different in various fruits. Anthocyanins are absorbed intact without cleavage of the sugar to form the aglycone. The proportion of the dose that appears in the urine is quite small (<0.1%). Plasma levels of anthocyanins are in the range of 1-120 nM following a meal high in anthocyanins, but fasting plasma levels are generally nondetectable. Information is limited as to possible metabolites of anthocyanins in the human. A number of antioxidant-related responses are reviewed in animal models as well as in the human. Anthocyanins can provide protection against various forms of oxidative stress in animal models, however, most of the health-related responses have been observed at relatively high intakes of anthocyanins (2-400 mg/kg BW).