How forever chemicals silently damage the brain

Health experts are raising alarms about ‘forever chemicals,’ a class of synthetic compounds known as per- and polyfluoroalkyl substances (PFAS). They are found in countless everyday products and are increasingly linked to neurological harm. From nonstick cookware, water-resistant clothing, and even food packaging, these chemicals do not break down in the environment or the human body.

A new study from the University of Rochester has added to growing concerns over forever chemicals. The study published in the European Journal of Neuroscience, found that even short-chain variants may have long-term impacts on brain development, especially in males.

History of forever chemicals

PFAS, developed in the 1940s, became popular for their resistance to heat, water, and oil. Used in products ranging from Teflon pans to cosmetics, dental floss, and fast-food wrappers, these PFAs add convenience. However, it came at the expense of health. National Health and Nutrition Examination Survey (NHANES) data indicates widespread PFAS exposure in the US population, with detectable levels in more than 98 % of their blood, due to exposure over decades. These PFAS are linked to a range of health issues, including developmental issues in babies and kidney cancer.

One PFAS, perfluorohexanoic acid or PFHxA, is made up of a shorter chain of molecules and is thought to have less of an impact on human health. The new study, however, suggests otherwise, and has revealed its potential to damage the brain.

How PFAs affect the brain

The new study by the researchers from the Del Monte Institute for Neuroscience at the University of Rochester found that early life exposure to PFHxA may increase anxiety-related behaviors and memory deficits in male mice. “Although these effects were mild, finding behavioral effects only in males was reminiscent of the many neurodevelopmental disorders that are male-biased. This finding suggests that the male brain might be more vulnerable to environmental insults during neurodevelopment,” Ania Majewska, PhD, professor of Neuroscience and senior author, said in a statement. The study also found that males are more often diagnosed with neurodevelopmental disorders such as autism and ADHD.

Forever chemicals linked to anxiety and memory loss

Male mice exposed to higher doses of PFHxA showed mild developmental changes, such as a decrease in activity levels, increased anxiety-like behaviors, and memory deficits. The effects were, however, not found in females that were exposed to PFHxA.
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The researchers followed these mice into adulthood. What they found was striking. In male mice, PFHxA exposure affected its behaviour long after the exposure stopped. This suggests that PFHxA exposure could have effects on the developing brain that have long-term consequences. “This work points to the need for more research in short-chain PFAS. To our knowledge, PFHxA has not been evaluated for developmental neurobehavioral toxicity in a rodent model. Future studies should evaluate the cellular and molecular effects of PFHxA, including cell-type specific effects, in regions associated with motor, emotional/fear, and memory domains to elucidate the mechanistic underpinnings,” Majewska added. PFHxA, though a shorter chain, has been found to be persistent in water.