Meat, dairy, fish, and shellfish consumption and per- and polyfluoroalkyl substance (PFAS) exposure in the U.S. population.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants for which consumption of animal-derived foods represents an important exposure pathway. Using nationally representative data from the U.S. National Health and Nutrition Examination Survey (NHANES) 2003-2020, we examined associations between intake of meat, dairy, fish, and shellfish and serum PFAS concentrations. Total serum PFAS showed an approximately 75% decline over the study period, primarily reflecting reductions in perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Shellfish consumption was the strongest dietary predictor of higher total and individual PFAS concentrations, with dose-response relationships, while meat intake was modestly associated and fish intake showed weak or inconsistent associations. In contrast, higher dairy intake was linked to lower total PFAS and reduced odds of elevated PFAS, particularly for PFOS, perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFUA), and perfluorodecanoic acid (PFDeA). Demographic patterns revealed higher PFAS among males, older adults, and Non-Hispanic White and Black participants, with lower concentrations observed in later survey cycles. These findings indicate that, while regulatory actions contributed to population-level declines, specific animal-derived foods-especially shellfish-remain important determinants of PFAS exposure, and the inverse association with dairy warrants further investigation.