Unsettling levels of microplastics discovered in human brains

Microplastics are becoming more and more of a concern as researchers are discovering them in almost every facet of life, and now a new study has pointed to the presence of microplastics in... human brains.

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It was only last year that researchers from the University of Mexico discovered microplastics in human testicle tissue, and now a new study published in the scientific journal Nature Medicine has revealed through sample analysis microplastics in the human brain tissue. The tissue was collected from people in 2016 and 2024, and according to the study, each of the brain samples contained microplastics and even smaller plastics called nanoplastics. Notably, the more recent samples contained 50% more plastics than the older samples.

The discovery of microplastics in the brain isn't totally new, as researchers penned a study in 2024 that detailed their presence, but this new study has looked at how microplastics can enter the brain, and according to the researchers, inhalation is a key factor. The researchers explain that when individuals inhale microplastics, which can be present in something as innocuous as indoor dust, the microplastics can travel through the nose to the olfactory bulb, a region of the brain responsible for processing smells.

Unfortunately, the microplastics are capable of passing the blood-brain barrier, a protective shield around the brain designed to prevent harmful substances from entering and damaging the brain. Researchers previously believed only the smallest microplastics could pass the barrier, but according to the study, even larger microplastics are capable of passing it. Notably, dementia patients were discovered to have 3 to 5 times more microplastics in the brain than those without dementia