sauce, but fermented soybeans show considerably higher concentrations, with tempeh having the highest isoflavone content. Other dietary sources of isoflavones include chick pea (biochanin A), alfalfa (formononetin), and peanut (genistein). Isoflavones are also found in foods of animal origin such as dairy products, meat, eggs and seafood, but the overall contribution to total intake is low. In countries using the chorleywood bread process, such as in the UK, bread is a source of isoflavones from soy. In plant tissue, they most often occur as glycosides or their respective malonates or acetyl conjugates, rendering them even more water-soluble (see isoflavone-7-O-beta-glucoside 6"-O-malonyltransferase). The latter forms are unstable and are transformed, e.g. by decarboxylation. Often when leguminose plants are challenged with viral or fungal infections, the water-soluble transport forms are hydrolyzed to the respective aglycones at the target site. Research The consumption of isoflavones-rich food or dietary supplements is under preliminary research for its potential association with lower rates of postmenopausal cancer and osteoporosis in women. Use of soy isoflavone dietary supplements may be associated with reduction of hot flashes in postmenopausal women. Soy isoflavones can act as substrates for thyroid peroxidase, thereby competitively inhibiting thyroid hormone production. Despite the frequent use of isoflavone supplements, there are insufficient data on safety and adverse effects. Isoflavones have GRAS status in the United States. In a risk assessment of isoflavone supplements for post-menopausal women, the European Food Safety Authority found no adverse effects with intakes up to 150 mg/d, although it criticized the lack of data. See also Cladrin Equol Glycitein Isoflavonoid Phytochemical Rotenoids References Phytoestrogens