Background information on the COT Working Group on Phytoestrogens and draft report

Wednesday 9 October 2002

In April 2000, the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) convened a working group to advise on the human health implications of dietary phytoestrogens.

Phytoestrogens are chemicals naturally produced by some edible plants, notably soy. They are present, to varying extents in the UK diet. In the body, they can mimic or block the action of human oestrogens, although they are much less potent. Phytoestrogens have been shown to cause fertility problems in animals ingesting phytoestrogen-rich diets. There is concern that phytoestrogens in soy-based infant formulae might have adverse effects on the sexual development of infants. However, there are no reports of adverse effects in populations whose traditional diet includes phytoestrogens such as the Japanese and Chinese. Indeed, it has been suggested in some scientific and medical literature that phytoestrogens may have beneficial effects on particular diseases.

The area of phytoestrogens is particularly complex. Therefore, Members of the Group were appointed with a broad range of expertise. The Working Group was Chaired by Professor Woods, Professor of Medicine at the University of Sheffield and the Membership included expertise in chemistry, developmental biology, endocrinology, epidemiology, nutrition, paediatrics and toxicology as well as two public interest representatives. The Membership of the Working Group is given below in full. The Group was supported by officials from the Food Standards Agency.

The Working Group agreed the following Terms of Reference:
“To advise on the health implications of dietary phytoestrogens through review of published scientific research and the Food Standards Agency’s phytoestrogen research programme.”

To address the Terms of Reference the following key points were considered:

• On the basis of current evidence, does ingestion of soy-based infant formula pose any risk for human infants?
• Are there health implications for other sub-groups of the population from the ingestion of dietary phytoestrogens?
• To consider the evidence for beneficial effects of dietary phytoestrogens.
• To make recommendations for further research.

The Working Group carried out a detailed review of the peer-reviewed scientific literature published up to 30th April 2002. The Group also considered submissions of evidence of health effects received during an external consultation conducted during 2000. The discussion papers considered by the Working Group (unless containing material supplied ‘in confidence’) and the minutes of the Group’s meetings have been published (see below).

The Working Group has completed its review and produced a report of its findings with recommendations. Comments on the draft Phytoestrogens and Health report are being sought from interested parties during a period of consultation, ending 3 December 2002. The Food Standards Agency’s advice on phytoestrogens will be informed by the Working Group’s report and the results of the consultation.