New research has found alarmingly high levels of microplastics in the human brain that could be linked to the global rise in Alzheimer’s disease.
The study, led by researchers at the University of New Mexico, has been published as a preprint online, meaning it has not yet been reviewed by other scientists.
But the findings are already causing alarm because the highest concentrations of microplastics were found in 12 brain samples taken from people who died with dementia, including Alzheimer’s disease, suggesting there could be a link.
Early findings suggest that the brain accumulates high levels of microplastics, highlighting the need for further research into how these particles impact human health.
Humans are exposed to microplastics (plastic fragments less than five millimetres in length) all the time.
They are in the air, water, food, cosmetics and practically everywhere. They also reach our organs when we breathe them or ingest them.
The researchers measured microplastic concentrations in 51 liver, kidney and brain samples collected in 2016 and 2024.
All samples contained particles, but brain samples contained seven to thirty times more than liver or kidney samples.
What’s more, 12 brain samples from people who died with dementia or Alzheimer’s contained up to 10 times more plastic by weight than healthy samples. The new Lede reported.
These early findings do not prove a link between microplastics in the brain and the incidence of dementia or Alzheimer’s.
But they do suggest the need for more research, as cases of these diseases are rising worldwide and the amount of plastic in brains has increased by more than 50 percent in the past eight years, the researchers wrote in their report.
In addition, previous studies in mice have linked nanoplastics (plastic particles even smaller than microplastics) in the brain to cognitive changes, Parkinson’s disease and some types of dementia.
A study of this type, published in the journal Scientific advances In 2023, they discovered that nanoplastics can interact with a protein called alpha-synuclein.
This protein is found in all brains and plays a role in communication between nerve cells.
Plastic particles can bind strongly to alpha-synuclein and cause it to form toxic clumps similar to those seen in Parkinson’s disease and other associated types of dementia.
In the preprint study, the researchers point to this mechanism as a possible driver of human brain disease that warrants further investigation.
In recent years, a wave of research has found microplastics in almost every part of the human body, including the heart, testicles, breast milk, placenta, liver, kidneys and brain.
Microplastics are practically everywhere, including in the air, food and water.
But this new study suggests that the brain accumulates unusually high concentrations of microplastics and that those concentrations are increasing over time.
“It’s quite alarming,” Matthew Campen, a toxicologist at the University of New Mexico and lead author of the study, told New Lede.
“There is much more plastic in our brains than I ever imagined or wanted to accept.”
Scientists still do not fully understand how microplastics affect human health.
But Another recent study suggests that microplastics in the arteries may increase the risk of heart attack and other cardiovascular problems.
And chemicals commonly found in plastics have been linked to a range of health problems, including cancers, metabolic disorders, attention deficit hyperactivity disorder and fertility problems.
In theory, increasing amounts of microplastics in the brain could be influencing global trends in neurological diseases such as Alzheimer’s, a form of dementia.
Global dementia cases are on track to triple by 2050, according to a 2022 study published in The Lancet journal on public health.
But more research is needed to link microplastics to this trend.
There are numerous risk factors for dementia and Alzheimer’s, including age, genetics, head trauma, hearing loss, and others.
But there is currently no evidence to suggest that the accumulation of microplastics in the brain is one of these risk factors.
This study provides a new incentive for research into how microplastics affect human brain health, as it could be important for understanding the global rise in dementia and Alzheimer’s cases.