Plastic is a daily part of modern life. Now, it’s also part of your body — and brain — according to researchers at the University of New Mexico.
For a recent study published in Nature Medicine, they analyzed donated brain tissue. Samples from people who were diagnosed with dementia had up to 10 times more microplastics in their brains than those without dementia.
Microplastics are small plastic pieces that typically range in size from 5 millimeters (about the size of a pencil eraser) to 1 nanometer (a tiny fraction of the width of a single human hair). Microplastics can also degrade into nanoplastics, which are even smaller, at less than 1 nanometer.
This study builds on previous research at UNM on microplastics in human tissues.
This time around, the researchers studied tissue samples from the frontal cortex of the brain, donated from autopsies by the New Mexico Office of the Medical Investigator. Older samples dated back to 2016, on average, and newer samples came from 2024.
Newer samples tended to contain more microplastics than older ones. This suggests that the amount of microplastics in brain tissue has increased over time — by 50% over the last eight years.
The researchers are careful to point out that while there is a strong association between dementia and the presence of microplastics in the brain, that doesn’t necessarily mean microplastics cause dementia directly. There could be something about the disease itself that causes more microplastics to accumulate in the brain.
Microplastics are also found in tissue from the liver and kidneys, but the amount is significantly greater in brain tissue, according to the study. It’s also greater in the brain than in placentas and testes, which have been shown to accumulate microplastics in previous studies.
Twelve types of plastics were identified in the analysis. The most common was polyethylene, which is typically used for packages and containers like bottles. Although it is believed that microplastics get into the body primarily through food, researchers aren’t sure how plastics travel to the brain.
The UNM researchers noted, however, that plastic pieces measuring 200 nanometers or less are small enough to pass through the blood-brain barrier. That’s the protective layer of cells that lines the inner surfaces of the brain’s blood vessels.
Matthew Campen, toxicologist and lead researcher of the study, says the increasing amount of microplastics in the body mirrors the increasing amount of plastic waste humans are creating.
He hopes the latest findings will be a wake-up call to consumers, who should be aware of the potential threat to human health:
“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.'”
To learn which foods are known to have high levels of plastic, read our story “8 Foods and Drinks That Are Full of Plastic (How Many Do You Eat?).”
Add a Comment