Products
Phytoestrogens are commercially available as dietary supplements, for example, in the form of capsules and tablets. They are found in various plants for example in nuts, seeds, fruits and vegetables. A typical example is soy.
Structure and properties
Phytoestrogens are a structurally disparate group of phytonutrients that resemble estrogens (estradiol) but do not have a steroidal structure.
Effects
Phytoestrogens act as agonists and antagonists at intracellular estrogen receptors. They bind much more weakly than natural estrogens such as estradiol and are generally active primarily at the ERβ estrogen receptor. In addition, several other mechanisms of action are discussed in the literature.
Indications for use
Possible areas of application discussed are (selection):
- For the treatment of menopausal symptoms, instead of estrogens.
- For the prevention of postmenopausal cardiovascular disease.
- For the prevention of osteoporosis.
- For the prevention of cancers, such as breast cancer.
How effective phytoestrogens are for these applications, however, is controversial.
Active ingredients
- Isoflavones, from soybeans, red clover and the kudzu root, e.g. genistein, daidzein, glycitein, formononetin, biochanin A.
- Prenyl flavonoids such as 8-prenylnaringenin in hops, known as the most potent phytoestrogen.
- Stilbenes, e.g. resveratrol
- Coumestanes, e.g. coumestrol, e.g. in legumes.
- Lignans, e.g. enterolactone or enterodiol, e.g. in flax.
Medicinal plants with phytoestrogens (examples):
- Cimicifuga
- Monk’s pepper
- Sp.
- Kudzu
- Flax
- Hops
- Maca
- Red clover
- Soy
Dosage
According to the package leaflet. To achieve an effect, the products must be taken regularly. In Asian countries, much more phytoestrogens are taken in with the diet than in Western countries.
Contraindications
- Hypersensitivity
- Infants, children and adolescents
- Pregnancy, lactation, childbearing
- Hormone-dependent cancers
We do not have a complete list of precautions.
Interactions
Phytoestrogens may influence the effects of natural estrogens because they bind to the same receptors.
Adverse effects
Taking high doses, especially in supplement form, may affect fertility in premenopausal women. In men, regular beer drinking has been associated with the development of gynecomastia and feminization. Whether regular and high-dose phytoestrogen therapy causes adverse effects has not been adequately documented. Phytoestrogens could be effective as endocrine disruptors.
