For the first time, researchers have found microplastics in the brain.
The latest study, published on Sept. 16 in 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 enter 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 their health risks is still in its early stages. More studies are needed to understand the potential health impacts.
Brain Plastic From Everyday Items
The tiny 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 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 years, and found microplastics in the olfactory bulbs of eight of them. The most common plastic found was polypropylene, making up nearly 44 percent of the samples. Polypropylene is used in items like food containers, straws, and some clothing fibers. Other plastics found included:
- Nylon/polyamide: 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, dividing the width of a human hair into 13 segments is about the size 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 from the nose to the brain, said Mauad, who is a professor of medicine at the Institute for Advanced Studies at the University of São Paulo.
She suspects that the microplastics could enter the brain using the same route. This direct pathway may allow plastic particles to enter the brain without passing through the blood-brain barrier, which acts as a protective shield to prevent the brain from harmful substances.
The microplastic particles may be able to interact with the olfactory nerves through this tunnel, she said.
Animal studies have shown that microplastics can affect brain areas involved in sensory processing and memory.
The nose-to-brain pathways have been observed with carbon air pollution particles, suggesting microplastics might do the same. Some animal studies indicate that microplastics could potentially cross the blood-brain barrier and affect various brain areas.
Health Implications Beyond Microplastics
The plastic problem is not only the microplastics, Mauad said. It’s also all the additives that are in the plastic. These additives, used to give properties like color and heat resistance, can be harmful. Some are carcinogenic or act as endocrine disruptors and can be released when plastics are heated, such as in the microwave.
Furthermore, “the presence of non-digestible microplastic particles with additives might provoke reactions,” particularly in a developing brain, she added.
In addition, 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, according to the study.
To minimize exposure to microplastics, 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.
- Avoid heating plastics: Avoid microwaving food in plastic containers or using plastic wrap in the microwave.
