[Flavonols, flavone and anthocyanins as natural antioxidants of food and their possible role in the prevention of chronic diseases].

Abstract

Flavonoids are non-nutritive compounds of plants that have been intensively investigated during the past years due to their possible protective effects against chronic diseases. In vitro studies were able to demonstrate for flavonols, flavones, and most recently also for anthocyanins a considerable antioxidative activity, mainly based on scavenging of oxygen radicals. Flavonols and anthocyanins are commonly found in European fruits and vegetables. In addition, black tea and red wine may have a high content of these compounds. Those food items are the main sources of flavonol consumption each contributing to a different degree to the overall intake. The absorption of aglycones has been established before. However, only recently could the absorption of flavonolglycosides be demonstrated. The mean intake of flavonols of the German population was calculated using data from the National German Food Consumption Survey. According to this analysis, the daily per capita intake was about 11.5 mg flavonols, mainly derived from fruits and vegetables, but also from black tea and red wine. Epidemiological studies have been directed to investigate the association between flavonol consumption and diseae risk. An inverse association between flavonol intake and mortality from myocardial infarction was observed. According to one of three studies, the flavonoid intake can be inversely correlated with cancer risk. This review summarizes the current knowledge on the occurrence, intake, bioavailability, and antioxidative properties of flavonols, flavones, and anthocyanins as well as the associations between flavonol intake and disease risks. Possible health related effects especially of flavonols are critically reflected, and the necessity of further research in outlined.