Bisphenol S, a common substitute for bisphenol A, is no safer than its equivalent. It accelerates the development of the fetus and excessively stimulates endocrinal neurons.
The bisphenol A substitute does not do any better than its cousin. Bisphenol S – increasingly used as legislation tightens – should also be considered an endocrine disruptor. Indeed, it interferes with the development of the reproductive system, explain California researchers in the journal Endocrinology. They shed light on the mode of action of this plasticizer on zebrafish.
Premature birth
Bisphenol A has been controversial since 2006, the date of the Chapel Hill Consensus. Its signatories indicate the deleterious effects of this product. In some studies, 95% of participants are exposed to it.
Of which act. On the French side, since 2010, plasticizers have been banned in baby bottles placed on the market. The country takes a further step on the 1er January 2015, by banning its use in any utensil or material intended to come into contact with food. Manufacturers then replaced BPA with other unregulated products this time.
But its derivative, bisphenol S, is not safer. Several studies have suggested its harmful impact, in particular on the development of embryos.
This latest study, conducted on zebrafish whose eggs are transparent, confirms the trend. Embryos developed much faster than normal when exposed to bisphenol S. In fish, this is similar to premature birth. The effect appears within 25 hours of including the chemical in the water.
A canary in a coal mine
Through the use of fluorescent proteins, it has also been possible to precisely track the development of brain cells that regulate puberty and fertility. In this regard, the results are edifying: the number of endocrine neurons increases by 40%, witnessing an excessive stimulation of the reproductive system.
According to Nancy Wayne, author of the study, these effects are likely to cause precocious puberty and disrupt the reproductive system. If this hypothesis is to be confirmed, the researcher puts forward a clear analogy: “The zebrafish must be seen as the aquatic version of the canary in a coal mine. “
His concern is not unjustified: his work has shown that bisphenol S – like bisphenol A – mimics the effect of estrogen… but also of thyroid hormones! “The thyroid hormone is crucial for the brain development of the embryo and fetus. You do not want to interfere with this hormone during development or in adulthood, ”said Nancy Wayne, contacted by Why actor.
Strictly similar effects
A multiple effect which must be reproduced in other species. If demonstrated, it could help explain the increase in premature births and early puberty. But, as René Habert, a reproductive toxicologist who has worked at length on the subject, underlines, “we have very little knowledge of the effects of BPS. On the BPA, we have about 9000 publications, against 90 on the BPS. ”
A bundle of concordant arguments must be collected, because work on humans is not possible. “This type of controlled study is not possible in humans because of ethical considerations,” said Nancy Wayne to Why actor. But we’re not that different in the way our cells respond to chemicals, including toxins. ”
A first lead was launched by René Habert’s team, which works at Paris-Diderot University and CEA (1): bisphenols A and S have the same effects.
René Habert, reproductive toxicologist: ” Bisphenol S has strictly the same effects as bisphenol A, at the same concentrations. Has BPA been replaced by such a dangerous product? The question is valid. “
In fact, these two bisphenols have an extremely close structure. “What happened is that we measured a parameter in vitro around 2005. It showed that BPS was less harmful than BPA, explains René Habert. But this parameter was very far from physiology. When you put everything back into an organism, the results differ. ”
Pending more conclusive results or stronger legislation, caution is advised. Bisphenol S is particularly used in plastic baby bottles. Their glass equivalents may be preferred.
(1) CEA: French Atomic Energy and Alternative Energies Commission
Bisphenol A: Its substitute BPS disrupts the development of the fetus – Study on zebrafish https://t.co/8pimXeGPiA pic.twitter.com/hOGHYWwJLt
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