| Popis: |
Phytoestrogens are composed derivatives of vegetables. The 2 main classes of interest to human health are lignans and isoflavones. Isoflavones exist in at least 15 different chemical forms and their effect on human health has been investigated to some extent (particularly, genistein and daidzein as high levels of these compounds are present in soybean). Isoflavones have similar structure to oestrogen and have the capacity to exert both oestrogenic and anti oestrogenic effects. They may block the effects of oestrogen in some tissues (e. g., the breast and endometrium), but act like an oestrogen in providing possible protection against bone loss and heart disease. Lignans are much more widespread in plant foods but investigation has been limited due to the complexity of measurement. The increasing interest in the use of the soybean and the phytoestrogens derived from the soybean is due to the results published on experimental animal actions, and in human case-control studies. There are many observational and epidemiologists studies that suggest the potential benefit of isoflavones on the menopause symptoms, the cardiovascular system, the osteoporosis and the estrogen dependent cancers, but many open questions exist. We must be very strict with certain observational studies by the possible influences of collateral factors to the isoflavones (exercise, type of diet, etc.), and attribute the beneficial effects may be due to own treatment. |
