In a disturbing discovery, scientists have found that human brain tissue may now contain measurable amounts of plastic, equivalent to a full plastic spoon, raising serious concerns about the long-term effects of microplastics on human health.
The findings came from a recent study in which researchers analyzed brain samples collected during autopsies in 2024. The samples showed significantly higher concentrations of plastic particles compared to earlier years, with scientists noting a 50% increase in microplastic presence compared to similar samples collected in 2016.
Co-lead author Matthew Campen, Regents’ Professor and professor of pharmaceutical sciences at the University of New Mexico, said the results are deeply concerning. “The concentrations we saw in the brain tissue of normal individuals, who had an average age of around 45 or 50 years old, were 4,800 micrograms per gram, or 0.48% by weight,” Campen explained.
“That’s the equivalent of an entire standard plastic spoon.” He added, “Our brains today are 99.5% brain, and the rest is plastic,” highlighting just how pervasive these synthetic materials have become in the human body.
According to the study, the brain contained seven to 30 times more microplastic fragments than other organs, such as the liver and kidneys. This raises critical questions about how plastic travels through the body and concentrates in such sensitive tissues.
The most concerning culprit? Nanoplastics—tiny plastic particles less than one micrometer in size. Campen warned that these minuscule fragments are capable of crossing the blood-brain barrier, a vital defense mechanism that protects the brain from harmful substances.
“Plastics love fats, or lipids,” Campen said. “One theory is that plastics are hijacking their way with the fats we eat, which are then delivered to the organs that really like lipids—and the brain is top among those.”
Plastic enters the human body through a variety of sources, including food packaging, clothing fibers, and indoor dust. These particles are inhaled, ingested, or even absorbed through the skin, and may lead to inflammation, hormone disruption, and other health issues.
Notably, researchers found that individuals diagnosed with dementia had up to five times more microplastic particles in their brain tissue. The particles were located not only in blood vessels but also embedded within immune cells of the brain.
“It’s a little bit alarming,” Campen acknowledged. “But remember that dementia is a disease where the blood-brain barrier and clearance mechanisms are impaired.”
He added, “We want to be very cautious in interpreting these results. The microplastics are very likely elevated because of the disease, and we do not currently suggest that microplastics could cause the disease.”
Further research is underway to determine more precise estimates and long-term implications. “We’re working hard to get to a very precise estimate, which I think we will have within the next year,” Campen said.