Phytoestrogens occur naturally in a wide variety of edible plants including soya. The chemical structure of the phytoestrogens closely resembles that of the human sex hormone oestradiol and, as a result, they can mimic or block the action of the human hormone although they are generally much less potent.
The phytoestrogen research programme was established in 1997 and the current objectives are to:
- establish whether phytoestrogens adversely affect human health, including reproductive function
- establish whether phytoestrogens have any beneficial effects on human health
This programme of research will provide more information about phytoestrogens and how they act in the human body. This will enable the Agency to:
- advise consumers on whether consumption of phytoestrogen-rich foods poses a risk to health, particularly for infants fed soya-based formulas
- advise consumers on whether consumption of phytoestrogens may be beneficial to health
- establish how phytoestrogens are metabolised in both adults and infants
- develop new tests to identify and measure phytoestrogens in foods
Phytoestrogens occur naturally in a wide variety of edible plants including soya. The four main types of phytoestrogen found in food are the isoflavones, the coumestans, the prenyl flavonoids, and the lignans. The chemical structure of the phytoestrogens closely resembles that of the human sex hormone oestradiol and, as a result they can mimic or block the action of the human hormone, although they are generally much less potent.
Phytoestrogens have been shown to cause some fertility problems in animals. However, there have been no reports of such effects in human populations, such as the Japanese or Chinese, whose traditional diet includes large quantities of soya. Indeed some scientific and medical literature suggests that phytoestrogens may have beneficial effects on adult populations. The current scientific evidence for either adverse or beneficial effects in humans remains equivocal.
The Food Standards Agency carries out work on phytoestrogens to find out more about their levels in food and how they act in the human body. The results obtained by the Agency will be used to provide health advice to the public and industry on the effect of consuming phytoestrogens either in foods (including soya-based infant formula) or dietary supplements.
The Committee on Toxicity of Chemicals in Food Consumer Products and the Environment (COT) set up a Working Group to review the health implications (risks and benefits) of dietary phytoestrogens. The Working Group reviewed both Food Standards Agency funded research as well as that conducted elsewhere and a draft report will be published in spring 2003.