UNM-Led Research Find Alarming Levels of Microplastics in Human Brains

Researchers led by University of New Mexico Health Sciences have revealed that human brain tissue contains high levels of microplastics, with a significant increase over the past eight years.

In an urgent scientific breakthrough, researchers led by the University of New Mexico Health Sciences have discovered that microplastics — tiny fragments of degraded polymers — have accumulated in human brains at alarmingly high levels. The concentration of these plastics in brain tissue has increased by 50% over the past eight years, signaling a growing environmental and health crisis.

In a study recently published in Nature Medicine, the research team led by Matthew Campen, Distinguished and Regents’ Professor at the UNM College of Pharmacy, analyzed brain tissue samples and found that plastic concentrations in the brain were significantly higher compared to other organs like the liver and kidney.

“This really changes the landscape. It makes it so much more personal,” Campen said in a news release.

The study’s findings are particularly concerning given that Campen’s team observed up to 10 times the amount of plastic in the brains of individuals diagnosed with dementia compared to those without the condition.

The researchers, however, cautioned that the study design does not establish whether microplastics cause dementia symptoms or simply accumulate more in diseased brains.

The research builds on a novel methodology developed by UNM researchers to identify and quantify microplastics in biological tissues.

This technique involved chemically dissolving brain tissue, centrifuging it to isolate plastic particles and then burning the particles through a process known as pyrolysis. The emitted gasses were analyzed chromatographically, allowing the identification of 12 different polymers, with polyethylene being the most common.

To visually examine the tissue samples with high polymer concentrations, the team used transmission electron microscopy. This revealed clusters of sharp plastic shards measuring 200 nanometers or less, which are small enough to infiltrate the blood-brain barrier.

Campen emphasized the potential risks posed by these particles, which might obstruct blood flow in brain capillaries or interfere with neuronal connections, potentially contributing to dementia-related protein aggregation.

“We start thinking that maybe these plastics obstruct blood flow in capillaries,” he added. “There’s the potential that these nanomaterials interfere with the connections between axons in the brain. They could also be a seed for aggregation of proteins involved in dementia. We just don’t know.”

The findings raise questions about how microplastics enter the human body. Campen suspects ingestion through food, particularly meat, is a major source.

“The way we irrigate fields with plastic-contaminated water, we postulate that the plastics build up there,” he added.

It appears that plastics concentrate in the food chain, especially in commercially-produced meat.

Microplastics tend to accumulate in the fat cells of the brain’s myelin sheath, which insulates neurons and plays a crucial role in signal transmission. This might help explain why brain concentrations are higher than in other organs.

Despite ongoing global plastic production, the presence of micro- and nano-plastics in the environment is projected to increase, as existing plastics degrade over decades. Campen believes that these revelations should catalyze concern and action against this global health threat.

“I have yet to encounter a single human being who says, ‘There’s a bunch of plastic in my brain and I’m totally cool with that,’” he added.

The comprehensive research highlights an urgent need for further investigation into the effects of microplastics on human health and calls for immediate action to reduce plastic waste and contamination.