Scientists Identify Microplastics in Human Brains — Found More Often in Dementia-Linked Tissue

Microplastics and 'Glassy Blobs' Found in Human Brains

Neuropathologist Dr. Elaine Bearer became intrigued after observing unidentified "glassy blobs" in the brain tissue of two people who had dementia, a discovery first reported by Chemical & Engineering News. Unable to determine the composition of those masses, Bearer sent samples to a University of New Mexico lab led by researcher Matthew Campen, which was already testing brain tissue for microplastics.

Analyses indicated that brain tissue associated with dementia contained roughly five times the amount of microplastics compared with samples from people without dementia. Building on those findings, Bearer and collaborators developed a microscopy method that identified the mysterious masses as microplastics and nanoplastics.

"This is the first time ever" that these kinds of masses observed by clinicians have been identified as plastic, Bearer told Chemical & Engineering News.

Researchers emphasize that these results are preliminary. Although the investigated dementia-linked samples showed a heavier microplastic burden, scientists have not established that microplastics cause dementia. Larger, controlled studies are needed to confirm the association, determine how plastics enter and accumulate in brain tissue, and clarify potential biological effects.

What we know about microplastics and health

Microplastics—particles smaller than five millimeters, and nanoplastics at even smaller scales—are now found throughout the environment and in people. Studies have detected these particles in organs and circulating in the bloodstream after inhalation or ingestion.

Groups such as the Oceanic Preservation Society note that micro- and nanoplastics may disrupt cellular function, trigger inflammatory pathways, and generate reactive oxygen species—processes that can contribute to chronic disease. However, concrete links to specific illnesses like dementia remain unproven.

Implications for wildlife and the environment

Microplastics affect wildlife as well as people: animals can inhale or ingest particles, which can harm individual organisms and contribute to biodiversity loss and ecosystem stress.

Practical steps to reduce exposure

While science continues to investigate health risks, individuals can reduce plastic exposure at home. Recommendations from sources including Blue Cross Blue Shield of Vermont include:

• Avoid microwaving food in plastic containers.
• Use a certified filter for tap water where appropriate.
• Choose clothing made from natural fibers instead of synthetics when possible.
• Reduce single-use plastics and household plastic waste; consider making simple DIY cleaners.

Bottom line: The identification of microplastics and nanoplastics in human brain tissue is a novel and concerning finding that warrants further research. It highlights the pervasive reach of plastic pollution and underscores the need for careful, larger-scale studies to understand any health consequences.