Phytoestrogen safety under scrutiny

Britain's Food Standards Agency (FSA) reports this week that the Committee on Toxicity (COT) is consulting on a draft report that looks at the implications for human health of phytoestrogens in our diet. The group recommends more research and a greater check on infant formulae.

Present to varying extents in our diet, phytoestrogens are chemicals naturally produced by some edible plants, notably soy. In the body they can mimic or block the action of human oestrogens, although they are much less potent, writes the FSA.

Evidence suggests that phytoestrogens could cause fertility problems in animals ingesting phytoestrogen-rich diets. There is also concern that phytoestrogens in soy-based infant formulae might have adverse effects on the sexual development of infants, adds the agency.

But there are no reports of adverse effects in populations, such as the Japanese and Chinese, whose traditional diet includes phytoestrogens and a body of scientific thought suggests that phytoestrogens may have beneficial effects on particular diseases.

COT, an independent committee that advises the Food Standards Agency on toxicological risks of chemicals to humans, set up the Working Group on Phytoestrogens in April 2000 to review the Agency's​ research programme on phytoestrogens and scientific research published on the subject.

Key points investigated were whether soy-based infant formulae pose a risk to infants; if there are health implications for other groups of people from dietary phytoestrogens, and whether there are benefits from consuming phytoestrogens.

The Working Group's recommendations include that soy-based infant formulae should only be given to infants for clinical reasons, and that doctors and other health-care workers are made aware of the potential interactions between phytoestrogens in these formulae and thyroid function.

The consultation will run until 3 December 2002.