Menarche to menopause

It is known from the Asian region that a diet rich in soya effectively prevents hot flushes and women suffer less from menopausal symptoms than women who are used to a European diet. This is probably due to secondary plant substances in the soyabean. Isoflavones and lignans have a similar molecular structure to oestrogens. They can bind to oestrogen receptors in the body and convey both an oestrogenic as well as anti-oestrogenic effect, although not to the same extent as a hormone replacement therapy. Apart from alleviating menopausal symptoms, it is debated whether isoflavones might also have positive effects on bone density, the cardiovascular system and cognitive functions, as well as having cancer-preventive properties.

To what extent the effects of the Asian diet can be copied is not entirely clear yet. While people in Southeast Asia have, since childhood, been used to a soya-rich diet with up to 60 milligrams of isoflavone per day, the average European’s normal diet provides less than two milligrams per day. Higher concentrations are usually only achieved with dietary supplements. These are often advertised as »gentle hormone therapy« for women with menopausal symptoms. The most common are products made from soya or red clover, which contain relatively high concentrations of isoflavones such as daidzein, genistein and glycitein. But also wheat germ, rhubarb root, hops or linseed have a weak phytoestrogenic effect and are available as food supplements.

An absolutely certain relief from menopausal symptoms has so far not been proven for any plant ingredient with an oestrogenic effect. For this reason, the Federal Institute for Risk Assessment (BfR) currently does not recommend taking isoflavones. The safety of using isoflavones as food supplements has not been sufficiently proven, especially when taken over a longer period of time or in isolated and high-dose form. The team around Patrick Diel from the German Sport University Cologne is warning against an uncontrolled intake of different preparations in the »Bundesgesundheitsblatt« (Federal Health Paper). Sometimes women may take so much that they exceed many times over the amounts recommended by the manufacturers, the authors write. Phytoestrogens are in principle not suitable for women who are or were ill with breast cancer. Here, the guideline »Peri- and Postmenopause - Diagnostics and Interventions« of the German Society for Gynaecology and Obstetrics refers to St. John’s wort, whose effectiveness against hot flushes could be proven in small studies.