A recent study revealed a high concentration of microplastics in human brain tissue, with some samples containing as much as a teaspoon of plastic, raising concerns about their potential impact on health. The study was published in Nature Medicine.
Researchers analyzed a total of 91 brain samples collected from deceased individuals, detecting plastic particles in all of them, with concentrations higher in brain samples than in the liver and kidneys. On average, seven grams of microplastic particles were found in the brains examined.
The study, led by Professor Matthew Campen and his team at the University of New Mexico, compared the plastic content in brain samples taken from cadavers who died in 2016 to those prepared in 2024. They found higher concentrations of microplastics in brain and liver samples from 2024, indicating an increase in accumulation over time, IFLScience reported.
Between 2016 and 2024, the average concentration of plastics in post-mortem brains increased by approximately 50%, from 3,345 micrograms per gram to 4,917 micrograms per gram, with brain samples from 2024 containing higher concentrations than those from 2016.
"The concentrations we saw in the brain tissue of normal individuals, who had an average age of about 45 or 50 years, were 4,800 micrograms per gram," said Campen. "This is the equivalent of an entire standard plastic spoon."
In the case of the brain samples, all from the frontal cortex, they contained higher concentrations of plastic particles—described as splinters—than in liver and kidney tissues, with levels in the brain reaching 30 times higher than in other organs.
The most common plastic found in the study was polyethylene, which is used in plastic bags and food and drink packaging, and was also the most frequently detected microplastic particle in the samples.
Microplastics and nanoplastics, despite their small size, are found in air, water, food, cosmetics, clothing, and dust, originating from everyday plastic products that decompose.
The increase in nanoplastics in human brains is concerning because plastics contain many compounds and impurities whose effects on human health have not been well studied.
Researchers are particularly concerned about the potential link between microplastics and neurological health. In 12 brains of people diagnosed with dementia, microplastic levels were found to be between three and five times higher, although they clarified that this does not necessarily mean that microplastics cause dementia.
"Although a cause-and-effect relationship between plastic particles and dementia is not established, the findings raise questions about the possible health consequences of exposure to plastics, particularly in the brain," DW reported.
"There is not enough data to make firm conclusions on the occurrence of microplastics in New Mexico, let alone globally," said Oliver Jones, Professor of Chemistry at RMIT University in Melbourne. He also noted that "the main analytical method used to measure plastics is prone to giving false results as fats, which the brain is mainly made of, give the same products as polyethylene, the main plastic reported."
Despite these concerns, the researchers emphasize that their findings underscore the need for more comprehensive studies on the effects of microplastics on human health. "Plastic pollution is no longer just an environmental issue; it's now a human health concern."
This article was written in collaboration with generative AI company Alchemiq