Report examines impact of phytoestrogens on health

Thursday 1 May 2003

The independent scientific Committee on Toxicity (COT) has published a report on the possible health implications of phytoestrogens in our diet.

Phytoestrogens are compounds produced naturally by some edible plants, most notably soya. In the body, they mimic or block the action of the human hormone oestrogen, although they are much less potent.

Extensive research worldwide on phytoestrogens has led to many conflicting reports in the scientific and popular press on the risks and benefits of consuming phytoestrogen-rich foods. In animals, exposure to large quantities of phytoestrogens has been shown to adversely affect fertility, leading to concerns that similar effects could occur in humans, particularly babies fed soya-based infant formulas.

In contrast, studies on populations that traditionally consume diets rich in phytoestrogens (for example Japanese and Chinese) suggest that they may have a beneficial effect on osteoporosis, cardiovascular disease and some cancers.

To make sense of the contrasting reports, an expert working group of the COT examined all the available information on the possible health effects of phytoestrogens.

It specifically looked at whether phytoestrogens pose a risk to infants fed soya-based formulas, whether there are implications for other groups of people and whether there are benefits from eating phytoestrogens.

In its report, the Working Group recommended that the Department of Health, which has responsibility for infant health and feeding practices, reviews its advice on the use of soya-based infant formulas.

The Group also concluded it is possible that phytoestrogens could adversely affect people with hypothyroidism and considered that, despite many claims that phytoestrogens have a beneficial impact on health, the evidence does not convincingly support this view. Further research to address specific knowledge gaps was recommended.

The COT Phytoestrogens and Health report is being presented to the FSA Board at its open meeting on 8 May 2003. The Board will be invited to consider various actions in response to the report's findings.