By now, you've no doubt heard that modern living is filling our bodies with microplastics. But an alarming study now shows just how much of the non-degradable particles are in our brains, and how much higher they are in dementia patients.
The study, led by researchers from the University of New Mexico, looked at dozens of samples of post-mortem liver and brain tissues taken from both men and women in 2016 and 2024. It found that in terms of the liver, there were, on average, 142 micrograms per gram (µg/g) in the 2016 samples. The brain for the same sample period contained 465 µg/g.
Just eight years later, in 2024, liver levels had skyrocketed to 3,420 µg/g on average, while the amount of microplastics in the brain had increased by a factor of roughly 10, reaching 4,763 µg/g. On average, the total amount of plastics found in the brain in each of the 2024 samples is about the same amount found in a disposable plastic spoon, say the researchers.
What's perhaps even more concerning is that post-mortem brain tissue samples taken from individuals with dementia had concentrations of microplastics that were three to five times higher than those without the condition.
"The dramatic increase in brain microplastic concentrations over just eight years, from 2016 to 2024, is particularly alarming," notes Dr. Nicholas Fabiano from the University of Ottawa's Department of Psychiatry, lead author of a commentary that accompanied the publication of the findings in the journal Nature Medicine. "This rise mirrors the exponential increase we're seeing in environmental microplastic levels."
Fabiano and his team also say there's cause for alarm in the fact that some of the plastics they found were smaller than 200 nanometers, which allowed them to cross the blood-brain barrier and accumulate in cerebrovascular walls and immune cells.
Beyond this study, previous research has found miniscule plastic particles in every single type of human tissue tested, with other papers linking these microplastics to everything from brain inflammation to low male fertility. Still, research on how our "plasticization" is affecting our health is in the early stages and more work needs to be done.
"We need more research to wrap our heads around microplastics – rather than wrapping our brains in them – since this could be one of the biggest environmental storms most people never saw coming," said Dr. David Puder, host of the Psychiatry & Psychotherapy Podcast and co-author on the commentary paper.
Until more is known about how plastic behaves inside our bodies, the researchers recommend taking common sense approaches like not using tea bags made from plastic, not heating food in plastic containers in the microwave, and shifting away from drinking out of plastic water bottles.
"Bottled water alone can expose people to nearly as many microplastic particles annually as all ingested and inhaled sources combined," says commentary co-author Brandon Luu, an Internal Medicine Resident at the University of Toronto. "Switching to tap water could reduce this exposure by almost 90%, making it one of the simplest ways to cut down on microplastic intake."
Source: Genomic Press via EurekAlert