Several grams of microplastics in human brains; More in people with dementia: study
Researchers at the University of Mexico have found microplastics in human brains, and even more in the brains of people with dementia. The complete human brain potentially contains several grams of microplastics, amounting to “the equivalent of a plastic spoon,” Matthew Campen, a Dutch researcher involved in the study, told the Volkskrant. The study was published in the scientific journal Nature.
The scientists examined the brains of people who died between 2016 and 2024. They detected approximately 5,000 micrograms of plastics per gram of brain tissue. People who died in 2024 had up to 50 percent more microplastics in their brains than those who died earlier.
The researchers also examined the brains of 12 deceased people with dementia. They found three to five times more microplastics than in people without dementia. That does not necessarily mean there is a causal link, but the researchers found it worth noting.
Neurotoxicologist Remco Westerink explained to the Volkskrant that with dementia, substances from outside penetrate the brain more easily. That could explain the larger amount of microplastics.
The study found no significant differences for other variables like age, gender, cause of death, or ethnicity. The most commonly found microplastic in the study was polyethylene, which is used in packaging materials like plastic bottles.
The scientists also found microplastics in other parts of the human body, such as the kidneys, but in much lower quantities. They noted that the liver and kidneys can remove plastic from the body, but it is unknown whether that is possible for the brain.
Microplastics are very tiny pieces of plastic, up to a few millimeters in size. They are created when a piece of plastic breaks down into smaller pieces. Because plastic doesn’t decompose, it sticks around in nature. Microplastics enter the human body through food, drinks, and the air.
Very little is known about how harmful microplastics are to humans. The Dutch public health institute RIVM previously recommended more research on the topic.
