Plastic Minds: How Microplastics Are Sneaking Into Our Brains
Monday, March 10, 2025.
In the grand tradition of humanity stuffing itself with things it probably shouldn’t, scientists have now confirmed that our brains—once believed to be the domain of existential dread, forgotten passwords, and questionable life choices—are also stockpiling microplastics.
Yes, tiny synthetic hitchhikers have made their way past every evolutionary firewall designed to keep nonsense out of our heads, and they’re settling in for the long haul.
A study published in Nature Medicine has taken a good, hard look at human brain tissue and found microplastics—those microscopic remnants of modern convenience—nestled deep in the frontal cortex.
While previous research has shown these omnipresent polymers invading our livers, kidneys, and even placentas (because of course they have), this latest discovery raises the uncomfortable question: What exactly are these plastic squatters doing in the human brain, and should we be worried? (Answer: Probably.)
Plastic, Plastic Everywhere—and Now It’s in Your Thoughts
For decades, we’ve watched microplastics proliferate like an invasive species of our own design.
They are the glitter of the modern era—everywhere, indestructible, and increasingly found in places no one wants them.
The air we breathe, the water we drink, the soil that grows our food—all marinated in the fine dust of consumer capitalism’s greatest achievement: plastic.
Scientists have long suspected that microplastics were making their way into our bodies, but until recently, we lacked the tools to confirm just how much we were accumulating or whether our vital organs were playing unwilling hosts to these industrial hitchhikers.
That changed when a group of researchers at the University of New Mexico Health Sciences, led by toxicologist Matthew Campen, devised a method to detect and measure microplastics in human tissue.
Previously, they’d confirmed microplastics in placentas and testes (because if there's a frontier, science will boldly go there). Now, they’ve turned their attention to the brain—and what they found isn’t pretty.
The Great Plastic Migration: Brain Edition
Using tissue samples stored by the New Mexico Office of the Medical Investigator, researchers compared brain tissue from 2016 with more recent samples from 2024. They focused on the frontal cortex—the seat of complex thought, decision-making, and now, apparently, plastic accumulation.
To extract and analyze these unwanted guests, scientists dissolved the tissue into a soupy mixture, spun it at high speeds in a centrifuge, and then subjected the remains to a 600-degree Celsius inferno. The resulting gas was fed into a mass spectrometer, which identified 12 different types of polymers lurking in human grey matter. As a final insult, electron microscopes revealed jagged, sharp-edged plastic fragments—some barely larger than a virus—embedded in brain tissue.
And the levels? Disturbingly high. In 2024, the median amount of microplastics in brain samples was 4,917 micrograms per gram. In 2016, it was 3,345 micrograms per gram—a 50% increase in just eight years.
For comparison, liver and kidney samples from 2024 contained a paltry 433 and 404 micrograms per gram, respectively. The dominant plastic was polyethylene, best known for its starring roles in shopping bags, food packaging, and that island of floating garbage haunting the Pacific Ocean.
What Happens When Your Brain is Part Plastic?
No one knows for sure, but the prognosis isn’t great.
The study found that brain tissue from folks diagnosed with dementia contained up to ten times more microplastics than tissue from those without cognitive decline.
While correlation isn’t causation, the potential implications are unsettling.
Could microplastics be clogging up neural highways? Interfering with synaptic connections? Acting as a catalyst for neurodegenerative diseases?
Campen suspects as much. “We start thinking that maybe these plastics obstruct blood flow in capillaries,” he explained. “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 study’s findings align with previous research on animals. In fish, nanoplastic exposure has impaired movement and hunting ability. In mice, prolonged exposure led to memory deficits, brain inflammation, and the kind of protein buildup associated with Alzheimer’s disease.
If these trends hold true for humans, the implications are staggering.
We Are What We Eat (And Breathe, And Drink)
The leading suspect in this grand heist of neural integrity?
Food—specifically, meat. Campen theorizes that plastics infiltrate the food chain through irrigation, feed, and soil contamination, creating a closed-loop system of plastic recycling within our own biology.
“The way we irrigate fields with plastic-contaminated water, we postulate that the plastics build up there,” Campen noted. “We feed those crops to our livestock. We take the manure and put it back on the field, so there may be a sort of feed-forward biomagnification.”
Other primary sources of microplastic exposure include bottled water (which is to plastic consumption what chain-smoking was to lung cancer), processed foods, seafood, and, perhaps most insidiously, the very air we breathe.
Can We Detox Our Brains?
As for reversing the damage, the options are slim.
Current research hints that some plastic-related chemicals—like bisphenol A—can be excreted through sweat, leading to speculation that exercise or sauna use might help. However, no direct evidence suggests that humans can actively clear microplastics from their systems. In other words, once the plastic's in, it might be in for good.
A separate commentary in Brain Medicine underscored the urgency of understanding what, if anything, we can do to limit our exposure and remove these materials from our bodies. Nicholas Fabiano, from the University of Ottawa’s Department of Psychiatry, put it bluntly: “The dramatic increase in brain microplastic concentrations over just eight years, from 2016 to 2024, is particularly alarming. This rise mirrors the exponential increase we’re seeing in environmental microplastic levels.”
His colleague Brandon Luu added a more pragmatic suggestion: “Switching from bottled water to tap water could reduce exposure by almost 90%.” Another pro tip: stop microwaving food in plastic containers unless you have a deep-seated desire to season your dinner with nanoplastic confetti.
The Big Question: What Now?
What’s clear is that microplastics have infiltrated every facet of modern life, from our oceans to our organs.
What’s less clear is whether we’ll take this knowledge and act—or simply continue accumulating plastic until future autopsies reveal that human beings, like so many broken Barbie dolls, are more synthetic than they realized.
“We need more research to wrap our heads around microplastics—rather than wrapping our brains in them,” quipped David Puder, host of the Psychiatry & Psychotherapy Podcast.
Time will tell whether this becomes one of the great, ignored environmental crises of our era. But given our track record, we might just keep rolling along, plastic brains and all.
Be Well, Stay Kind, and Godspeed.
REFERENCES:
Nihart, A. J., Garcia, M. A., El Hayek, E., Liu, R., Olewine, M., Kingston, J. D., Castillo, E. F., Gullapalli, R. R., Howard, T., Bleske, B., Scott, J., Gonzalez-Estrella, J., Gross, J. M., Spilde, M., Adolphi, N. L., Gallego, D. F., Jarrell, H. S., Dvorscak, G., Zuluaga-Ruiz, M. E., ... & Campen, M. J. (2024). Bioaccumulation of microplastics in decedent human brains. Nature Medicine. https://doi.org/[DOI number]
And for the commentary:
Fabiano, N., Luu, B., & Puder, D. (2024). Human microplastic removal: What does the evidence tell us? Brain Medicine.