Plasticisers found in many objects we use every day can cause severe brain damage, according to a study published in Nature (1). Biologists from the University of Bayreuth, Germany, showed that even small amounts of plasticisers can interfere with the transmission of signals in nerve cells in the brains of fish. The researchers went even further, saying that it is highly likely that plasticisers have a similar effect on the brains of adult humans.
Bisphenols are common plasticisers found in everyday objects, from food packaging and baby bottles to plastic containers and toys. Researchers already know that some health risks are associated primarily with bisphenol A (commonly known as BPA). Now, Bayreuth researchers demonstrated for the first time that these plasticisers have more severe effects on nerve cells than previously thought. And it turned out it’s not just BPA, but there are other plasticisers like bisphenol S (BPS) that are equally dangerous and can cause permanent damage to the nervous system.
The team detailed their findings from experiments with goldfish. Their focus was on the largest type of nerve cells in the fish rain, known as Mauthner cells. These cells play a vital role for fish, processing all sensory stimuli, including when predators are close. During evolution, these cells become particularly robust and can usually compensate for damage and maintain their functions.
This makes it even more worrying when it only took one month of exposition to BPA or BPS to alter all aspects of neuronal function in these fish, including affecting acoustic and visual stimuli. “We were surprised how many vital brain functions in fish are affected by the plasticisers used in numerous industries. This damage, as we were able to show, does not occur immediately. However, when the brain cells are exposed to small amounts of BPA or BPS for a month, the damage is unmistakable,” says Elisabeth Schirmer, first author of the study.
To make matters worse, this study shows clearly and alarmingly that both BPA and BPS can affect functionality in the mature brain. This is to add to what researchers already knew about the damaging effect of plasticisers on babies’ developing brains. “The findings obtained through studies on fish brains justify the assessment that BPA and BPS can also seriously damage the brains of adult humans. Against this background, it is essential that science and industry develop new plasticisers to replace these bisphenols, while being safe for human health,” says Dr Peter Machnik, from the Department of Animal Physiology at the University of Bayreuth.
Given these results, the team calls for the development of alternative products that do not carry the same risks to the nervous system. What’s more, they believe their technique using goldfish could be a valuable and inexpensive tool to test how new plasticisers affect brain cells.
(1) Schirmer, E., Schuster, S. & Machnik, P. Bisphenols exert detrimental effects on neuronal signaling in mature vertebrate brains. Commun Biol4, 465 (2021). https://doi.org/10.1038/s42003-021-01966-w