The study, "Associations between perfluoroalkyl substances and multiple sclerosis in U.S. cohorts compared with NMOSD, MOGAD, and healthy controls," was published in Environmental Research.
Led by Farren Briggs, Ph.D., Sc.M., associate professor in the Department of Public Health Sciences, the multi-institutional study examined associations between exposure to per- and polyfluoroalkyl substances (PFAS) and multiple sclerosis (MS), with findings suggesting the relationship may be particularly pronounced among women.
“Multiple sclerosis is a chronic autoimmune disease in which the immune system attacks the protective covering of nerve fibers, disrupting communication between the brain and body,” explained Dr. Briggs. “While both genetic and environmental factors are known to contribute to disease development, many potential risk factors remain undiscovered.”
PFAS are a group of widely used synthetic chemicals found in products such as nonstick cookware, water-resistant fabrics and food packaging. They have also been detected in drinking-water systems serving more than 200 million Americans. Because they break down slowly in the environment and the human body, they are often referred to as "forever chemicals."
To better understand whether PFAS exposure was uniquely associated with MS, researchers compared PFAS levels among individuals with MS, neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and healthy controls. Although these conditions share some neurological symptoms, they are distinct diseases with different underlying mechanisms.
The research team found that women with MS had higher levels of two PFAS compounds—perfluorohexane sulfonic acid (PFHxS) and perfluorooctanoic acid (PFOA)—than the comparison groups. The findings were particularly notable for PFHxS, which emerged as the compound with the strongest and most consistent associations with MS across analyses.
“PFAS are nearly ubiquitous in modern environments, yet we know surprisingly little about their potential role in neuroimmune diseases,” said Dr. Briggs. “Our findings suggest that certain PFAS may be associated with MS in women and warrant further investigation as potentially modifiable environmental risk factors. Importantly, these associations were not observed in related neuroinflammatory diseases, raising important questions about whether PFAS may influence biological pathways that are more specific to MS.” The study also explored potential biological pathways that may help explain the association.
Researchers observed that associations between PFAS levels and several steroid-related metabolites differed between women with MS and healthy women. They also identified preliminary gene-expression patterns associated with neuronal and synaptic pathways. Together, these findings suggest PFAS exposure may influence hormone-related processes and biological pathways involved in neurological health.
While the findings do not establish a causal relationship, they provide additional evidence supporting further investigation into how environmental contaminants may influence neurological disease.
The researchers noted that future studies involving larger and more diverse populations, as well as long-term follow-up, will be needed to better understand the timing and potential mechanisms underlying the observed associations.
The study involved collaborators from the University of Miami, Mayo Clinic, Vanderbilt University, East Carolina University, Case Western Reserve University, the University of Texas at Austin, the University of Southern California and other academic and industry partners.
Written by Deycha Torres Hernández, published June 24, 2026.
