A team of scientists detected microplastics in the human brain at concentrations much higher than in other organs.
These microplastics can lodge in the human body, including the liver, kidneys, placenta, and testicles. However, researchers have found that the brain is the most affected.
Microplastics—plastic particles smaller than 5 millimeters—have been infiltrating the environment at an alarming rate as global plastic use increases.
Microplastic levels in the environment have skyrocketed in recent decades, with current plastic production exceeding 300 million tons per year and approximately 2.5 million tons floating in the world’s oceans in 2023, more than ten times the levels in 2005.
A new study published in Nature Medicine concluded that microplastics and nanoplastics (even smaller, ranging from 1 to 1,000 nanometers) accumulate at higher levels in the human brain than in the liver and kidneys.
The study also found significantly higher concentrations of microplastics and nanoplastics in 2024 samples compared to 2016 samples, and higher levels in the brains of people diagnosed with dementia.
How do we ingest microplastics?
Researchers suspect that most microplastics in the body are ingested through food, particularly meat, because commercial meat production tends to concentrate plastics in the food chain.
“Because of how we irrigate fields with water contaminated by plastics, we believe microplastics accumulate there,” said Campen. “We feed those crops to our livestock. We take the manure and return it to the field, so there may be a kind of biomagnification and buildup of microplastics.”
The research team found high concentrations of plastic in meat purchased at grocery stores, he added.
Campen stated that the new findings should raise alarms about a global threat to human health, even though people often pay little attention when warned about environmental contaminants typically measured in parts per trillion.
What effect do microplastics have on the brain?
Scientists discovered that brain tissue from people diagnosed with dementia had up to 10 times more microplastics than others in the study, Campen noted in a statement.
However, “while there is a clear correlation, the study’s design cannot prove whether higher levels of microplastics in the brain caused dementia symptoms,” as they may simply have accumulated more due to the disease process itself, the research notes.
Scientists also found plastic fragments measuring 200 nanometers or less, not much larger than a virus.
“They are small enough to cross the blood-brain barrier,” Campen said, adding that it is unclear how the particles are transported to the brain.
How do microplastics affect the human body?
Scientists say they are also unclear about what effects microplastics may have on the body, considering they are inert particles and frequently used in medicine, such as in artificial joints.
However, they do not rule out that the physical characteristics of these particles could be the real problem, causing some form of chemical toxicity.
Health implications
While research on the effects of microplastics in the brain is still limited, current findings suggest they could have negative long-term consequences for neurological health.
These effects could include a higher risk of neurodegenerative diseases such as Alzheimer’s and Parkinson’s, as well as learning, memory, and behavioral problems.
Steps to reduce microplastic exposure
While it is difficult to completely avoid microplastic exposure, there are some measures we can take to reduce it:
Reduce plastic consumption: Opt for reusable products instead of single-use plastics.
Wash synthetic clothing less frequently: Or use a laundry bag to trap microfibers.
Avoid food packaged in plastic: Choose fresh and bulk foods.
Do not heat food in plastic containers: Use glass or ceramic instead.
Support initiatives to reduce plastic pollution: Participate in cleanup campaigns and demand that companies adopt more sustainable practices.
It is important to note that research on the effects of microplastics in the brain is ongoing, and more studies are needed to fully understand the health risks. However, current findings suggest it is prudent to take steps to reduce our exposure to these contaminants and protect our neurological health.
