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Understanding the debate on endocrine disruptors

These days you read a lot about the impact of so-called “endocrine disruptors” on health. Media are reporting on it and politicians and other stakeholders are regularly making statements about the cost of these substances on our societies. At European level, early July 2017, the European Commission adopted criteria to determine whether a substance should be identified as an endocrine disruptor. Here are some basics in order to better understand the debate.

What is the difference between endocrine active and endocrine disrupting substances?

Certain natural, the so-called “phyto-estrogens”, and man-made substances, co-called “endocrine active” substances, can exhibit properties that mimic hormones’ properties. However, not all of them fulfil the widely accepted World Health Organisation (WHO)’s definition of an endocrine disruptor.

  • Endocrine active substances can interact or interfere with the endocrine system, without however producing harmful effects. Endocrine active substances include both organic and synthetic substances; for example, such substances can be found in carrots, soy beans or coffee. Synthetic substances that have been found to be endocrine active include a wide range of chemicals, very often intentionally used in medicines (e.g. substitutes for thyroid hormones, birth control pills, etc.), often because of their endocrine active properties that can help address some medical conditions.
  • Endocrine disruptors are substances that produce an adverse effect by influencing the hormone system. This distinction is critical, and is being addressed by regulators. The widely accepted WHO’s definition of an endocrine disruptor stipulates: “An endocrine disruptor is an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny, or (sub) populations.” In other words: any observed and validated negative effect on health must be a direct result from the endocrine activity on the organism.

What about BPA?

In laboratory settings, it is indeed possible to show very low estrogen-like activity of BPA via exposure to very high levels of BPA. Therefore, BPA could be considered an endocrine active substance. The exposure levels at which effects occur are unrealistically high and would never be reached in normal daily life. However, the levels of BPA to which consumers are exposed are so minimal that they are not negatively affected by such exposure. In fact, the “power” or the “potency” of this low endocrine activity is by orders of magnitude lower than that of endocrine active substances you can find in soybeans, carrots or coffee.

For BPA, a comprehensive scientific evaluation, which follows weight-of-evidence principles, was carried out by the European Food Safety Authority (EFSA) in 2015. EFSA’s independent researchers reviewed all available scientific studies on BPA, including the literature on potential endocrine-related effects of BPA. On endocrine disruption EFSA’s expert panel concluded that “scientific knowledge of how BPA behaves in humans was still unclear and there was no single explanation for how BPA potentially affects humans. Therefore, based on the WHO criteria, it was not considered possible to conclude that BPA is an endocrine disruptor”.

You may wonder whether it is necessary to ban the consumption of coffee and soybeans due to their potential impact on the endocrine system. No need – as with BPA, there is no risk in the small amounts we are exposed to these endocrine active substances in our everyday lives.

See also:

Science & Risk Assessment

Regulatory Framework