This is the key question that scientists are trying to answer at the moment. The trouble is that it’s easy to find all kinds of things that can be shown using different tests to interact in some way with hormones, or the glands that produce them, or the receptors the hormones connect with. While such tests often provide valuable information to improve our understanding of how things can interact with the endocrine system, they in no way show that there will be an effect on people, or that it will lead to harm.
Cabbage, soya beans, sprouts and even beer and wine are just some of the many foods that contain ‘phyto-oestrogens’ which tests show can mimic or inhibit the natural female hormone oestrogen. But there’s no evidence at all that people who consume these are being feminized or suffering unwanted effects that might be related to interference with the endocrine system.
Then there’s the contraceptive pill: the active ingredient is specifically designed to alter the normal reproductive cycle in women by temporarily interfering with hormone action, and would be rated as a highly potent ‘endocrine disruptor’. But its effects on the hormone system are intentional and beneficial and there’s no evidence that it’s causing other endocrine related diseases or harmful effects.
More and more substances are currently being branded as ‘endocrine disrupters’ by campaign groups based on isolated tests. Often these show weak interactions that are thousands or millions of times less powerful than natural female hormones or the ‘pill’. So it’s important to ask ‘what evidence is there that this substance, in the amounts I’m likely to be exposed to it, is capable of causing harm’?
There’s currently a debate at EU level about what regulations might be needed, and already some EU laws prohibit ‘endocrine disruptors’ from being used in certain fields. The UK is rightly insisting that there must be clear evidence of the ability to cause harm in a whole organism (i.e. not just cells in test tubes), as defined by the World Health Organisation (WHO), before a substance is formally classified as a potential ‘endocrine disruptor’, which could automatically result in it being restricted or banned.