Microplastics Found in Human Brain for the 1st Time

A new study from Brazil reveals that microplastics might enter the human brain through the nose, with unknown impact on brain function.

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For the first time, researchers have found microplastics in the brain.

The latest study, published on Sept. 16 in the Journal of the American Medical Association (JAMA), identifies microplastics in the olfactory bulb, the region of the brain located above the nose and responsible for our sense of smell. This discovery raises new concerns that these tiny particles might be slipping past the brain’s protective barriers and entering deeper brain regions, potentially harming brain health and neurological function.

“Our analysis of olfactory bulbs from deceased patients in São Paulo confirmed the presence of microplastics,” physician and principal investigator Thais Mauad told The Epoch Times. This suggests a potential route for these particles to enter the brain.

Mauad also highlighted the uncertainty surrounding the health effects of these findings. “We still don’t know the consequences,” she said, noting that animal studies suggest potential neurotoxicity and links to neurodegenerative diseases.

While microplastics have been found in various body tissues, including the lungs, gut, liver, placenta, testicles, and bloodstream, research on the potential health impacts is still in its early stages.

Brain Plastic From Everyday Items

The types of plastic particles found in the human brain’s olfactory bulbs are often present in everyday items like food packaging and clothing. Given the widespread presence of these particles in the air, Mauad and the researchers proposed that people may be getting microplastics in their brains by breathing them in through the nose, similar to the way certain air pollution particles have been found to enter the brain.

Plastic does not break down completely; it turns into smaller pieces over time, contaminating the air, food, and water.

Mauad said that people are exposed to more plastics when indoors.

“We are massively exposed to microplastics,” she said. “We breathe in more indoors than outdoors.”

The researchers examined the brains of 15 deceased individuals, aged 33 to 100, and found microplastics in the olfactory bulbs of eight of them. The most common plastic found was polypropylene, present in nearly 44 percent of the brain samples. Polypropylene is used in items like food containers, straws, and some clothing fibers. Other plastics found included:

• Nylon/polyamide, which is used in clothing, carpets, and industrial products.
• Polyethylene, found in plastic bags, bottles, and containers.
• Polyethylene vinyl acetate (EVA), used in flexible packaging and some footwear.

The microplastics measured between 5.5 and 26.4 micrometers—much smaller than very fine dust. To put this in perspective, the width of a human hair is about 13 times larger than the width of the smallest microplastics found.

Slipping Past the Brain’s Barrier

There is a small passage in the nose that allows olfactory nerves to cross into the brain, said Mauad, who is a professor of medicine at the Institute of Advanced Studies at the University of São Paulo in Brazil.

She suspects that microplastics could enter the brain using this direct pathway, allowing them to bypass the blood-brain barrier that protects against exposure to harmful substances. The particles may also be able to interact with the olfactory nerves through this tunnel, she said.

Animal studies have shown that microplastics can cross the blood-brain barrier and affect brain areas involved in sensory processing and memory.

Health Implications Beyond Microplastics

Plastics could be harmful to brain health not only because of microplastics, but also because of the numerous additives they contain, Mauad said. These additives, used to give properties like color and heat resistance, can themselves be harmful. Some are carcinogenic or act as endocrine disruptors and can be released when heated, such as in the microwave.

Furthermore, “the presence of nondigestible microplastic particles with additives might provoke reactions,” particularly in a developing brain, she said.

Previous research has linked fine particulate matter in the air to brain issues such as dementia, with some diseases like Parkinson’s potentially beginning with nasal symptoms. Both fine particulate matter and microplastics have shown potential to negatively impact brain development in experiments.

To minimize one’s exposure, Mauad recommends:

• Limiting use of plastics: Reduce the use of plastic containers and packaging, especially for food and beverages.
• Choosing natural fibers: Opt for clothing and textiles made from natural materials rather than synthetic fibers.
• Not heating plastics: Avoid microwaving food in plastic containers or using plastic wrap in the microwave.