More than 1,000 isoflavones have been identified in plants. Of these, four specific isoflavones have been shown to possess significant individual and specific biological activity. These are: genistein, daidzein, formononetin and biochanin A.
What are the dietary sources of isoflavones?
Isoflavones are found mainly in legumes, such as red clover, lentils, split peas, chick peas, broad beans and soy. However, not all legumes contain all four important isoflavones. For example, red clover contains all four isoflavones whereas soy contains only the two isoflavones daidzein and genistein. The isoflavone content of food also varies, for example red clover also contains 10 to 20 times the quantity of isoflavones found in soy.
You can help boost levels of phytoestrogens through having a diet high in legumes rich in isoflavones such as lentils and soy.