What if BPA was only the tip of the iceberg?

Bisphenol A (BPA) alternatives in “BPA-free” products could be more dangerous than BPA. 

Last year, Breast Cancer UK awarded a research grant to Dr Michael Antoniou, along with his research associate Dr Robin Mesnage, at King’s College London, to evaluate the endocrine disrupting properties of herbicides and compounds used to make plastics. In this science blog, Dr Mesnage explains the background to their most recent findings, which have just been published as a preprint.

More than 80 years ago, bisphenol A was discovered to have oestrogen hormone-mimicking effects. Discarded by the pharmaceutical industry, it was used as a plasticizer and added to polycarbonate plastic or epoxy resins for decades before some researchers rediscovered its ability to disturb the hormonal system. Thousands of studies are now reporting adverse health effects of BPA in humans, including reproductive and neurobehavioural disorders. Due to mounting evidence of harm and public pressure, plastics manufacturers are phasing out BPA and “BPA-free” products are now abounding in supermarkets.

What if BPA was only the tip of the iceberg?

How plastic is manufactured has not changed significantly, and new bisphenols have been introduced to replace BPA. We are getting exposed to BPS, BPAP, BPAF, BPB, BPZ… the list is growing with the imagination of industry chemists. These compounds are already widely found in human urine, raising questions about their safety. BPA alternatives are structurally related to BPA. We, at King’s College London, wondered if they could have comparable endocrine disrupting effects. To test our hypothesis, we have compared the endocrine disrupting effects of the most common alternatives on breast cancer cells.

We used various technologies to monitor the function of breast cancer cells exposed to BPA alternatives. We investigated if the BPA alternatives could increase the proliferation of breast cancer cells. This is a hallmark of two-thirds of breast cancers which have their proliferation driven by oestrogen receptor alpha activation. Our findings revealed that all alternatives could substitute for oestradiol in promoting cell growth through oestrogen receptors in human breast cancer cells. The activities of all the genes were monitored using a technique known as transcriptional profiling, which measures the activity of thousands of genes simultaneously. The breast cancer cells exposed to BPA alternatives displayed the hallmarks (or signature) of endocrine disrupting effects through oestrogen receptors. Surprisingly, BPAF, BPB and BPZ, contained in “BPA-free” plastics, were more oestrogenic.

Our discovery has critical value for society.

We decided to publish the study before peer review (1). We believe public health data should be made public as soon as possible, and we encourage all scientists to do the same. Sharing scientific discoveries before they get published in peer-reviewed scientific journals, where it is impossible to amend them, also improves the quality of the studies because it allows critical input from the scientific community.

The research carried out by our team at King’s College London reveals that BPA-free products are not necessarily safer. BPA is the tip of the iceberg. Our discovery has profound consequences, both at the scientific and societal levels. The clinical relevance of hormone-dependent breast cancer progression should be investigated. A global push to remove all bisphenols from consumer products would be necessary to protect the population’s health.

1. Robin Mesnage, Alexia Phedonos, Matthew Arno, Sucharitha Balu, J. Christopher Corton, and Michael N Antoniou (2017). Transcriptome profiling reveals bisphenol A alternatives activate estrogen receptor alpha in human breast cancer cells. BioRxiv preprint posted March 2, 2017. http://biorxiv.org/content/early/2017/03/02/112862

If you want to donate to our animal-free research find out more here.