Australian experts have labeled a new study which found that the plastic ingredient bisphenol-A (BPA) could harm a baby’s brain development while in utero misleading and irrelevant’.
According to the Food Standards Australia New Zealand site, BPA can be found in some food and drink packaging. It is used to protect the food from contamination as well as to extend the shelf life. It can seep through into food and beverages in small quantities.
Researchers in the US published a new study today in the journal PNAS. They found that BPA could inhibit the expression of a particular gene in the development and growth of the central nervous systems of babies while they are still embryos.
In a press release, Duke University Medical Centre’s lead author, Wolfgang Liedtke, said that BPA could impair the development and function of the central nervous systems.
The study focused on a protein named KCC2 that helps to reduce the amount of chlorides as the neurons develop in the embryonic mind.
If KCC2 levels do not meet the required levels, chloride levels can remain high. This can cause damage to neural circuits as well as prevent nerve cells from settling into the correct position in the brain.
The study showed that BPA exposure suppresses the gene necessary to produce KCC2, resulting in problematic levels of chlorides.
The authors suggested that BPA may have caused this because it increases levels of another protein, MECP2, which inhibits the function of the gene required to produce the correct amount of KCC2.
Researchers found that BPA exposure to female neurons was more severe than BPA exposure to male neurons.
“Our present findings, in which we are recording related results in rat, mouse, and human neurons, raise the question of whether BPA exposure could predispose to neurodevelopmental disorders including autism-spectrum-related diseases,” the study said.
BPA exposure can disrupt the development of the central nervous system by slowing the removal of chlorine from neurons. As the brain and an organism develop, the chloride level in nerve cells decreases. When exposed to BPA, however, the chloride is more slowly removed from neurons. The researchers also found that female neurons are more susceptible to BPA’s effects. Michele Yeo, Duke Medicine
Experts urge caution in interpreting.
Australian experts have cautioned Australians to be cautious when interpreting new findings.
This is an interesting study. It’s linkage with environmental exposure to Bisphenol A, however, is misleading. The concentrations used in this research are hundreds or thousands of times greater than the maximum permissible levels of BPA allowed in food.
This study is irrelevant to human exposure, even though it sheds light on gene regulation.
Professor Andrew Bartholomaeus of the University of Canberra School of Pharmacy, Adjunct professor of Toxicology, said that researchers “used techniques to bathe excised tissue in BPA in a form which is not found in the human body due to BPA ingested in food in a nonphysiologically significant environment.”
He said that BPA in food and drinks is rapidly and completely metabolized, so the cells of the body do not come into contact with free BPA.
The effects of BPA on animals were caused by the injection of BPA into their bodies or bloodstreams. They are not relevant for human exposure to BPA at minute levels in food and drinks.
Professor Ian Rae of the Faculty of Arts, University of Melbourne (and former President of the Royal Australian Chemical Institute) said that further research is needed.
The clinical results indicate that tissues sensitive to BPA at very low concentrations experience adverse effects. He said that it is unclear whether the tissues in question would be exposed to BPA in this manner, given normal consumption patterns and established elimination pathways.
“Population studies, of course, are impossible. The studies listed on the Food Standards Australia New Zealand website have shown very low levels of BPA toxicity. However, it is prudent to revisit them from time to time as this area of clinical study and new findings must be carefully evaluated.”
