A study published on April 19 in the journal "Nature Health" found that micro- and nanoplastic particles are present in almost every sample of living brain tissue studied in humans. According to the team of authors, this is the first direct evidence of plastic pollution in the brains of living patients. The results fit into a rapidly expanding body of scientific data that questions the potential link between plastic pollution and neurological disorders.
"Plastic in every brain": what the samples show
The study, led by Li R. and colleagues, covered 156 samples of pathologically altered brain tissue taken from 113 patients with brain tumors, as well as 35 samples of healthy brain tissue from five post-mortem donors. Microplastic was found in 99.4% of the samples from affected tissue and in 100% of the samples from healthy tissue. Scientists reported a higher concentration of plastic particles in the tissues located around the tumors, compared to healthy brain tissue, suggesting that in cancer patients, the impaired blood-brain barrier may allow plastic particles to pass more easily into the brain.
The team found a positive correlation between the total surface area of microplastic and the proliferation of tumor cells, but refrained from making categorical statements about a causal link. The new research builds on a fundamental article published in February 2025 in "Nature Medicine" by Matthew Kempen and his colleagues from the University of New Mexico. This work showed that brain tissue contains between 7 and 30 times more microplastic compared to samples from the liver and kidneys of the same people. In addition, the authors documented an increase in the concentration of microplastic in the brain by about 50% for the period from 2016 to 2024.
Growing concern about the link between microplastic and neurodegenerative diseases
The accumulation of plastic particles in the brain draws attention to a possible link with neurodegenerative diseases. Kempen's 2025 study showed that the brains of people diagnosed with "dementia" contain three to five times more plastic compared to the brains of people without this disease. However, scientists warn that such data should not be interpreted hastily: it is possible that the causal link is the opposite – dementia damages the blood-brain barrier and thus facilitates the penetration of plastic into the brain, and not plastic being the primary cause of the disease.
In a separate review published in March 2026 by researchers from the University of Technology in Sydney, five biological mechanisms were outlined by which microplastic can potentially damage the brain: activation of immune cells, strengthening of oxidative stress, disruption of the blood-brain barrier, disruption of mitochondrial functions and direct damage to neurons. "Microplastic practically weakens the blood-brain barrier and makes it more permeable," commented one of the authors of the review, Associate Professor Kamal Dua.
Calls for urgent further research
Despite the avalanche of growing evidence for the presence of microplastic in the human body, scientists remain cautious in their conclusions. "We do not believe that we can currently speak of a proven causal link between microplastic and dementia," Kempen stated in an interview with "Brain & Life" magazine. Other researchers also make methodological criticisms. A team led by Fazel Monif from the University of Padua published a response article in "Nature Medicine" questioning some aspects of Kempen's methodology and concluding that "the available data are not yet sufficient for definitive conclusions regarding the presence of microplastic in the human brain and its impact on health".
Despite the warnings of caution, the overall picture from the studies so far raises serious concern in the scientific community. "The levels of plastic we are finding in the brain are almost impossible to fathom," commented Andrew West, a neurobiologist at Duke University and co-author of the 2025 study. Against the background of the continued growth in global plastic production, scientists point out that the study of the mechanisms of penetration, accumulation and potential harm of these particles in the brain should become an urgent priority for public health.