[Potential health-protective effects of food-derived flavonoids].

The flavonoids similarly to the other phenolic substances are secondary products of the plant metabolism. Their basic role is the defence of the plant cell from different damaging agents such as UV light, fungus, insects, viruses and oxygen free radicals. Laboratory and epidemiological studies have proved their wide-range chemical, biological and biochemical effects. Their beneficial action is unquestionable in preservation of health and prevention of diseases. The author presents the chemical structure, biochemical effects of the most frequently studied flavonoids, their metabolism and bioavailability, the flavonoid intake of the population, and the possible side effect of the components.