While much attention on PFAS and neurological health has focused on children’s development, emerging research is examining PFAS effects on cognitive health in adults — including aging-related cognitive decline and dementia risk. This developing area of research provides additional perspective on the long-term importance of PFAS exposure reduction.
PFAS and Adult Brain Health
Cross-sectional studies examining associations between PFAS blood concentrations and cognitive test performance in adults have found mixed results, with some studies finding associations between higher PFAS and poorer cognitive function in older adults. The proposed mechanisms include PFAS effects on thyroid hormone (which is important for adult brain function maintenance), neuroinflammatory effects, and potential interactions with neurotransmitter systems.
Alzheimer’s and Dementia Research
Investigation of PFAS exposure and dementia risk is at an early stage. A 2023 study found associations between PFAS blood levels and cognitive decline trajectory in older adults over a 5-year follow-up period. While this and similar preliminary findings cannot establish causation, they are consistent with mechanistic research showing PFAS neurotoxicity in animal models and add to the growing picture of PFAS as a potential contributor to age-related neurological health outcomes.
Implications for Adult Filtration Decisions
For adults — particularly those in middle age and beyond, who face both longer historical cumulative PFAS exposure and increasing concern about cognitive aging — reducing ongoing PFAS intake through certified water filtration represents a sensible precautionary measure. Given the multi-decade timescale of cognitive decline, actions taken now to reduce PFAS exposure may have consequences for brain health that extend far into the future, even if current research cannot yet definitively quantify those benefits.