science
Study Finds Higher PFHxS Levels Linked to Increased MS Odds in Women but Not Men
A review of blood samples from 439 U.S. participants found elevated PFAS compounds associated with higher multiple sclerosis odds, particularly among women. The August 2026 study in Environmental Research reported the strongest link with PFHxS.
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A study published in the August 2026 issue of Environmental Research found higher blood levels of perfluorohexanesulfonic acid associated with increased odds of multiple sclerosis, with the link appearing only among women. Newsweek reported that researchers analyzed samples from 439 U.S. participants for PFHxS, PFOA and PFOS.
Higher PFHxS levels corresponded to approximately 53 percent greater odds of MS overall and 56 percent greater odds among women. Participants with the highest PFHxS levels were more than 3.5 times as likely to have MS as those with the lowest levels. The same analysis showed participants with the highest PFOA levels were approximately 2.
A weaker association appeared with PFOS. Among men the PFAS-MS link was described as imprecise. An estimated 1 million Americans live with MS, according to a 2017 study that also found women accounted for 74 percent of diagnoses.
PFAS chemicals were first developed in the 1930s and remained largely unregulated until the early 2000s. Dr. David Hafler, a Yale professor of neurology and immunobiology who was not involved in the research, told Newsweek that MS results from interactions between more than 260 genetic variants and environmental factors.
He noted this is the second study showing an association between PFAS and MS risk, adding that the chemicals represent one risk factor rather than a sole cause. Hafler said further basic immunologic investigations will be important, as noted in the study itself.
