A new study has found a rising trend in microplastic contamination in human brain tissue, reflecting the exponential increase in plastic pollution over the past 50 years.
Researchers analyzed postmortem tissue from individuals who died between 1997 and 2024 and discovered micro- and nanoplastics in the brain, liver, and kidneys. The concentration of microplastics was significantly higher in brain samples, with an even greater presence in those from 2024 compared to 2016.
The study also noted that brain samples from individuals with dementia contained about six times more microplastics than those without the condition. However, researchers cautioned against assuming a causal link, as dementia-related brain damage could naturally lead to increased particle retention.
“Given the exponentially rising environmental presence of micro- and nanoplastics, this data compels a much larger effort to understand whether they have a role in neurological disorders or other human health effects,” said the research team, led by Prof. Matthew Campen at the University of New Mexico.
Microplastics, broken down from plastic waste, are found throughout the environment, from the highest mountains to the deepest oceans. Humans ingest them through food, water, and air, and they have been detected in blood, semen, breast milk, and even bone marrow. While the health effects remain unclear, some studies suggest potential links to strokes and heart attacks.
The most common plastic found in the brain samples was polyethylene, used in plastic bags and food packaging, accounting for 75% of the total plastic detected. Most particles were nanoscale shards and flakes.
Prof. Tamara Galloway from the University of Exeter highlighted the 50% increase in brain microplastics over the past eight years, noting it mirrors the rising global plastic production. “It suggests that if we were to reduce environmental contamination with microplastics, the levels of human exposure would also decrease, offering a strong incentive to focus on innovations that reduce exposure,” she said.
Prof. Oliver Jones at RMIT University in Australia called the findings significant but urged caution due to the challenges of analyzing microplastics in human tissue and the study’s relatively small sample size.
The research, published in Nature Medicine, underscores the urgent need to better understand how microplastics enter the body, how they are processed, and their potential health impacts, particularly on the brain.
