What is the difference between human estrogen and phytoestrogens?
Human estrogens include estradiol, estrone, and estriol. Estradiol and estrone are secreted by the ovaries and estradiol is the principle and biologically most active. The biological action of estrogens occurs by binding to estrogen receptor of tissues. The majority of phytoestrogens belong to a large group of flavonoids. Three classes of flavanoid, the coumestans, prenylated flavonoids and isoflavones, are phytoestrogens that possess the most potent estrogenic activity. A class of non-flavonoid phytoestrogens, the lignans has also been identified. Many flavonoids have a similar structure as Estradiol.
