The Major phytoestrogen groups – isoflavones, flavones, coumestans and lignans and its food sources. Definition and health benefits of phytoestrogens

Recently special attention has been paid to dietary fibre associated phytochemicals such as phytoestrogens. Epidemiological- and in vitro fermentation- studies and experiments with animals have suggested that the biologically activity of these compounds are associated with the prevention of different diseases. Till now phytoestrogens in cereals, legumes and oilseeds, especilally in rye, soy beans and flaxseed have been generally studied. According to researchers, a high daily intake of plant lignans is probably important for the intestinal conversion of plant lignans to the mammalian lignans enterodiol and enterolactone. Enterodiol and enterolactone decrease the risk of hormone-dependent diseases, such as breast and prostate cancer, because of hormone level changes are also important for the prevention of coronary heart disease. There are different opinions about the influence of soy isoflavones and their metabolites on human health. One group of researchers explain that the influence of soy isoflavones on humans has an anti-cancer effect while the other group advocates an opposite view. In the human organism soy isoflavones seem to work like estrogens and seem to stimulate hormone-dependent diseases. Therefore, dietary fibre and with them the associated phytoestrogens and their metabolites are actual the object of investigation. Special attention should also be paid to less investigated plant products which could be rich sources of phytoestrogens. In this area a lot of research has to be carried out to understand the phytoestrogens role in the disease prevention mechanism and to determine the recomended daily intake. Further solutions of the problem are linked with the development of new methods of investigation.