It's an unnerving thought, but the average brain may contain a spoonful of plastic.
A new study says the number of tiny bits of plastic found in human brains increased dramatically between 2016 and last year. The highest amounts were found in the brains of people who had dementia.
Dr. Ryan Cheung, a neurohospitalist and medical director of the stroke program at Texas Health Plano, talks about this with KERA’s Sam Baker.
Cheung: These microplastics are very small, less than 200 nanometers in size. The human hair is about 80,000 nanometers wide. So these things are very, very tiny.
Baker: Still, how do these get into our brain to begin with?
It's not entirely known. There are different routes of ingestion and inhalation. Perhaps, in the skin absorption. One of the most commonly cited ways is through ingestion.
Some of the materials that we use for food containers and storage, drinks and packaged foods are entered and absorbed to the gut.
And then there's also some thought to inhalation of tiny plastic particles from things like synthetic fabrics, dust, and pollution that are breathed in.
So we're talking what we think are solid objects, solid materials, but particles can come loose from that at any given time.
Yes, they get broken down in the body and make their way into the blood-brain barrier and penetrate through some of the small openings. And it can create an inflammatory response, which leads to oxidative stress and additional age-related mechanisms on the brain.
I was just about to ask you, how does this affect our health?
A lot of this work is still very early. But they found that patients with a label diagnosis of dementia had a higher concentration of microplastics in the brain. They're not sure about the cause and effect relationship of this, but it is thought that perhaps these individuals already have a weakened blood brain barrier to begin with, and that allows more plastics to permeate this and allows that to accumulate.
And it's also thought that plastics can cause inflammation and additional oxidative stress, which is already a known factor in things like Alzheimer's or maybe Parkinson's disease.
And it's similar to the story of asbestos, which itself is fairly inert, but it triggers a pretty significant inflammatory response in the body and specifically in the lungs.
I understand children, though, are considered at the greatest danger.
It probably has to do with the fact that their brains are still developing. They also have an increased risk of exposure to plastics and a lot of things that kids put into their mouths. A lot of the toys, and then perhaps things like formula and other bottles and plastic containers that are used and that can release plastic into the body.
Is there anything we can do about this, either to get rid of what we've accumulated or to prevent more accumulation?
There are some things that we can do to minimize our daily exposure.
Avoiding plastic containers where possible, especially avoiding microwaving or heating food in plastic that can cause more leaching of chemicals into food.
Using glass or ceramic containers, especially with hot food or beverages, and then using things like glass or stainless steel water bottles helps to reduce a lot of that leaching into liquids specifically.
And then there's some thought to using some natural fibers, things like wool or cottons, as opposed to some of the synthetic fibers, could potentially lead to less leaching from clothes.
And then things like filtering for air and proper ventilation inside your home.
You realize how scary this might sound to people, considering how much we use plastics and have used plastics over time.
Yeah, so I think reassurance is really important and that the long-term effects are still being studied.
So if I'm hearing you correctly, this isn't something to become fearful about, but something to be aware of and maybe take appropriate steps.
No need to cause any undue panic or alarm, but something to be aware of, and that there are some small things and that we can do ourselves today to limit our exposure.
RESOURCES:
You might have a spoon's worth of microplastics - in your brain.
Your brain is full of microplastics: are they harming you?
Microplastics Found in Human Brains
Copyright 2025 KERA
