We’re exposed to microplastics in myriad ways: Those tiny, degraded bits of plastic are in our soil, our water, even in our air. They then get into our bodies, lodging themselves in our organs—including our brains. An adult human brain can contain about a spoon’s worth of microplastics and nanoplastics, recent research found—not a spoonful, but the same weight as a disposable plastic spoon.
That amount was higher—by seven to 30 times—than the amount of microplastics found in other organs, such as livers or kidneys. The concentrations were even higher (by three to five times) in individuals diagnosed with dementia. And even more concerning, experts say, is how these levels have increased over time: Between 2016 and 2024, the concentration of microplastics in human brains increased by about 50%.
Those findings came from a study by University of New Mexico researchers that was recently published in the journal Nature Medicine. A new commentary, published today in the journal Brain Medicine, builds on that research by looking at a few big questions that arise when we learn we have lots of microplastics in our brains: How can we limit our exposure, and is there any way to remove these microplastics?
How to reduce microplastics exposure
The microplastics found in human brains included nanoplastics—particles smaller than 200 nanometers (a human hair, for contrast, is about 80,000 nanometers wide). They were also mostly made up of polyethylene, a commonly produced plastic used in everything from food packaging to drink bottles to plastic bags. That helps give an idea of what sorts of exposure could lead to these particles ending up in the brain, says Nicholas Fabiano from the University of Ottawa’s psychiatry department, and lead author of the commentary; Fabiano’s research focuses on the overlap between mental and physical health.
Bottled water is a particular source of these kinds of microplastics. Switching from that to filtered tap water could reduce your intake of microplastics from 90,000 particles per year to 4,000. (Though it’s not clear, the commentary authors note, if that would translate to a measurable drop in the amount of microplastics accumulated in our body tissues.) Plastic tea bags have also been found to release millions of microplastic particles when brewed, so avoiding those could also limit exposure. There are also microplastics in ultra-processed foods like chicken nuggets.
Storing and heating food in plastic containers can release lots of micro- and nanoplastics. “Switching to glass or stainless steel might be safer,” Fabiano says. Canned soup could also be a source of exposure, as cans are often lined with plastic. The authors also noted a 2011 study that found that after five days of eating canned soup, participants saw the levels of BPA (a chemical used to make plastic) in their urine increase more than 1,000%. (There has since been a decline in cans with BPA in the lining, but some new linings instead contain polystyrene.)
Because microplastics are even in our air—more than 60,000 such particles are inhaled by male adults per year, previous research has found—the authors also recommend using HEPA air filters.
Can we remove microplastics that are already in our brain?
The original study on microplastics in human brains had an interesting finding: There was no correlation between someone’s age and their microplastic levels. “That suggests people’s bodies are able to get rid of these microplastics in various different ways,” Fabiano says. (If there were a correlation, there would be a cumulative effect: The older someone is, the more microplastics in their brain.)
How exactly that happens, though, we still don’t know. “Is it through sweat? Is it through feces? Is it through urine?” Fabiano says. Prior research has found BPA in people’s sweat, suggesting that induced sweating could potentially remove those particles, but more research needs to be done, he says.
The commentary is a call for more research. For all the research identifying microplastics in the environment or in our bodies, there’s little on the health impacts of this debris. And what exists on that front focuses mostly on physical health. “If you have a spoon’s worth of plastic in your brain, surely there must be impact to your mental health,” Fabiano notes.
The original Nature Medicine article was a “step in the right direction,” he adds, for even looking at dementia patients and shedding light on the possible connection for diagnoses and microplastics. But it also raises more questions that researchers need to answer—not just on the impacts, but also if scientists should establish microplastics-exposure limits, and how else we could reduce or remove the microplastics already inside us.
“Right now, the microplastic-and-health research is still in its early days,” Fabiano says. “But so far, what the research has shown is that it’s certainly not a good thing to have microplastics.” The best thing for people to do in the meantime, he says, is to try to limit their exposure.
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