MICROPLASTICS IN THE HUMAN BRAIN

A GROWING THREAT

Recent research from the University of New Mexico Health Sciences has unveiled a concerning presence of microplastics in human brain tissue, with concentrations significantly higher than in other organs such as the liver and kidneys. A study published in Nature Medicine on February 3, 2025, analyzed brain samples from autopsies conducted between 2016 and 2024, revealing that microplastic levels in the brain have increased by approximately 50% over this period. On average, these samples contained about seven grams of microplastics—the equivalent weight of a plastic spoon.
nature.com

The study identified various types of plastics in the brain, with polyethylene being the most prevalent. Polyethylene is commonly used in products like plastic bags and packaging materials. Notably, individuals diagnosed with dementia exhibited up to ten times higher concentrations of microplastics in their brain tissue compared to those without dementia. While this correlation is evident, the study did not establish a direct causal relationship between microplastic accumulation and the development of neurodegenerative diseases.

The mechanisms by which microplastics enter and accumulate in the brain remain under investigation. One hypothesis suggests these particles may cross the blood-brain barrier, possibly through ingestion or inhalation, and subsequently accumulate in the brain's lipid-rich regions. Animal studies have indicated that microplastics can reduce blood flow in the brain and impair mobility, though these effects were observed to last only a few days.

The health implications of microplastic accumulation in human brain tissue are not fully understood. Potential concerns include obstructing blood flow in capillaries, interference with neural connections, and catalyzing protein aggregations associated with dementia. Given the rapid increase in environmental microplastic pollution, researchers emphasize the urgency of understanding exposure pathways and health consequences to mitigate potential risks.

Detecting rising levels of microplastics in human brain tissue shows the vital need for further research into their sources, pathways, and health effects. As microplastic pollution escalates globally, understanding its impact on human health, particularly neurological health, becomes increasingly critical.

Bioaccumulation of microplastics in decedent human brains (Nature Medicine, 2-3-25)

UNM Researchers Find Alarmingly High Levels of Microplastics in Human Brains – and Concentrations are Growing Over Time (UNM, 2-3-25)

Plastic shards permeate human brains (Science News, 2-3-25)