Experts have long touted BPA-free plastic water bottles as safer for human health, but a new study warns that might not be the case.
BPA – or bisphenol A – is a chemical commonly used in plastics that is known to disrupt hormones in the body, causing fertility issues, sexual development and other problems.
In addition to water bottles, it can be found in trash bags, food and drink containers, tableware and other products.
As the public grew increasingly concerned about BPA’s harmful effects, manufacturers began replacing it with ‘safer’ alternative bisphenols.
But two of the most widely-used alternatives – bisphenol S (BPS) and bisphenol F (BPF) – actually behave almost identically to the hazardous chemical they were designed to replace, new research has shown.
The findings suggest that these BPA alternatives are no less harmful than the real thing, disrupting hormones and leading to the same adverse health effects.
‘The use of these bisphenols should be discontinued due to the risks they may pose to human and animal health,’ said researcher José Villalaín from the Universidad Miguel Hernández in Spain.
Villalaín, a professor of biochemistry and molecular biology, used computer simulations to observe how BPA, BPF and BPS interact with cell membranes.
Understanding how these bisphenols interact with cell membranes is critical to understanding how they impact human health.
Cell membranes are the protective barriers that surround human cells. They control which chemicals can move in and out.
When toxic chemicals – like BPA – infiltrate these membranes, they can wreak havoc the health and functioning of cells.
Villalaín simulated 12 different systems, each with different amounts and arrangements of these chemicals as well as a modelled cell membrane designed with lifelike complexity.
He ran each simulation for 1,000 nanoseconds. During this time, he tracked the movements of every molecule and how they interacted with each other.
This allowed him to measure where the bisphenols positioned themselves, how they affected membrane fluidity and whether they formed clusters.
The study revealed striking similarities between how BPA, BPF and BPS interacted with the modelled cell membranes.
Villalaín published his findings in the Journal of Xenobiotics in September.
All three chemicals gravitated to the same location just beneath the membrane’s surface – roughly the width of a few atoms deep.
They also all made the membranes more fluid, and formed clusters when present at higher concentrations.
That clustering behavior is particularly concerning because it could affect cellular function.
Typically, the human body flushes out bisphenols within 24 to 48 hours.
Because these chemicals are present in so many of the products people use day to day, the human body is constantly exposed to them.
Long-term exposure can therefore cause these toxic chemicals to build up in organs, tissues and cells.
‘Since bisphenols tend to accumulate in the lipid phase [the part of the cell membrane where molecules responsible for transporting substances and chemical signals into and out of cells are located], the concentration of bisphenols found in biological membranes can be significant,’ Villalaín said.
His study adds to a growing body of evidence that suggests these chemicals might be ‘regrettable substitutions.’
But this research does not provide direct evidence of the harmful effects of BPF and BPS in humans, even through their identical behavior to BPA is a strong indicator that these three chemicals should also have identical health impacts.
Therefore, Villalaín’s study calls for further investigation of these alternative chemicals in order to gain a better understanding of their impact on human health.
