GROUNDBREAKING research has found that microplastics are accumulating in human brains at alarming levels, with concentrations increasing over time and potentially linked to dementia.
The presence of microplastics in human tissues has been a growing concern, and a recent study has confirmed their accumulation in the brain, liver, and kidneys of decedents. Scientists from the University of New Mexico and collaborating institutions analysed post-mortem samples from 52 individuals. Their research highlights a concerning trend: microplastic concentrations in the brain surpass those in other organs, raising questions about potential health implications.
To conduct the study, researchers obtained de-identified liver, kidney, and brain samples from autopsies performed in 2016 and 2024. Using advanced detection methods, including pyrolysis gas chromatography–mass spectrometry and electron microscopy, they identified microplastics in all three organs, with polyethylene being the dominant polymer. Notably, the median concentration of microplastics in brain tissue increased from 3,345 µg/g in 2016 to 4,917 µg/g in 2024 (p = 0.01). This significant rise aligns with broader environmental plastic pollution trends. Interestingly, microplastic accumulation did not correlate with age, sex, race, or cause of death, but individuals with dementia exhibited even greater plastic concentrations, particularly within cerebrovascular walls and immune cells. While no direct causal link has been established between microplastics and dementia, the findings suggest a need for further investigation.
These results underscore the urgency of understanding how microplastics enter and persist in the human body, particularly in the brain. While the liver and kidneys appear to clear some plastic particles, the brain’s ability to expel them remains unclear. The long-term health effects of microplastic exposure, including potential neurotoxicity, warrant further clinical and epidemiological studies. For healthcare professionals, these findings highlight the need for increased awareness of environmental pollutants as a factor in neurological health. As plastic pollution continues to rise, mitigation strategies, including reducing plastic exposure in food and water sources, could become an essential aspect of public health policy. Future research should focus on elucidating the mechanisms of plastic uptake and clearance in human tissues and evaluating potential interventions to limit exposure.
Katrina Thornber, EMJ
Reference
Nihart AJ et al. Bioaccumulation of microplastics in decedent human brains. Nat Med. 2025;DOI:10.1038/s41591-024-03453-1.
