Phytoestrogens.

Phytoestrogens have had a modest positive impact on bone tissue and on the development of osteoporosis in experimental animals. However, well-designed human studies are needed before making general recommendations.

European researchers have established a database on phytoestrogens within European diets. The database includes almost 300 foods commonly consumed in Europe. Included are isoflavones (genistein and daidzein), coumestrol, formononetin, biochanin A and lignans. Based on this database and the dietary intake in several countries, phytoestrogen intake in Europe is estimated to be less than 1 mg per day, compared to an intake of up to 100 mg per day in Asia.

Bioavailability studies confirmed that most phytoestrogens are readily absorbed by humans, but this varies somewhat, possibly due to a variability in gut microflora, diet and metabolism.

Contact: Francesco Branca, Instituto Nazionale di Ricerca per gli Alimenti e la Nutrizione (INRAN), Via Ardeatina, 546, 00178 Rome, Italy. Phone: [phone]. Fax: [phone]. Email: [e-mail].