Are There Microplastics in the Brain?
A 2025 study found them there. Researchers publishing in Nature Medicine on February 3, 2025 analyzed liver, kidney and brain tissue from autopsy specimens from 2016 and 2024, and reported that microplastic and nanoplastic concentrations in normal brain samples were 7 to 30 times greater than in livers or kidneys, and that brain samples from dementia cases showed even more.
The researchers said the total mass concentration of plastics in the brains they analyzed increased by approximately 50 percent over the past 8 years. The particles in these organs were mainly polyethylene, and electron microscopy showed the brain particles largely as nanoscale shard-like fragments. They found no correlation between total plastics and age at death, which did not support the idea that the particles simply build up over a lifespan.
The authors were clear about the limits. They wrote that the extent to which microplastics and nanoplastics cause human harm or toxicity is unclear, and that their data are associative and do not establish a causal role for such particles affecting health. Nature Medicine has since published an author correction to the article, on March 31, 2025, and a Matters Arising response to it, on November 13, 2025.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- StudyA 2025 Nature Medicine study reported that microplastic and nanoplastic concentrations in normal brain samples were 7 to 30 times greater than in livers or kidneys, and that brain samples from dementia cases showed even greater amounts. Nature Medicine ↗
- StudyThe study’s authors said the total mass concentration of plastics in the brains they analyzed increased by approximately 50 percent in the past 8 years, comparing autopsy specimens from 2016 and 2024. Nature Medicine ↗
- StudyThe authors wrote that their data are associative and do not establish a causal role for such particles affecting health, and that the extent to which these particles cause human harm or toxicity is unclear. Nature Medicine ↗
- StudyThe study found the particles in these organs primarily consist of polyethylene, and electron microscopy showed the isolated brain particles largely as nanoscale shard-like fragments. Nature Medicine ↗
- StudyThe authors said the lack of correlation between total plastics and age at death did not support the idea that the particles accumulate in the body over a lifespan. Nature Medicine ↗
- StudyNature Medicine lists an author correction to the article published on 31 March 2025 and a Matters Arising response published on 13 November 2025. Nature Medicine ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.