Microplastics are tiny particles of plastic found in food, water, the air and the body. In a study of 52 human brains, researchers found that microplastics can cross the blood-brain barrier and collect in deep brain regions.
Newer brains had more polymers in them than brains that were donated longer ago. Some brains were from 2024, and others were from 2016. The recent brains had more plastic, showing the problem is getting worse.
The researchers compared the amount of plastic in the brain to other organs, like the liver or kidneys. Although one might expect the blood-brain barrier to protect the brain, in some samples, the brain contained 30 times more plastic than the organs. The average amount of plastic in the brain was the equivalent of a small plastic spoon.
The brains of people with dementia had three to five times more microplastics than the brains of people without dementia. A brain with dementia often has impaired filtering processes. It’s unclear if the microplastics may have caused the dementia or if the effects of dementia led to a buildup of plastic in the brain. However, animal studies have found that microplastics were linked to memory impairment and cell stress in the brain.
The microplastics are individually microscopic. But, as small as they are, they still shouldn’t be able to cross the blood-brain barrier. The researchers believe the plastics may be hitching a lift on dietary fats that can cross the wall.
Another study on microplastics came out recently that is of interest to folks with blood sugar concerns. It’s an animal study. We always urge caution about drawing conclusions from animal studies, as a lot is different between animal models and humans. However, we can learn a lot from the studies.
The animal study looked at pigs. It found that exposure to PET, a plastic common in water bottles and food containers, can interfere with the pancreas. Even low daily doses of PET led to insulin resistance, pancreatic cell damage, free fatty acids, and more.
The researchers suggested that this was a new way that microplastics “may cause metabolic disturbances” and potentially heighten the risk of metabolic and blood sugar concerns.
At this point, microplastics are in our waterways, the soil and the air. There is no way to avoid them completely, but doing things like switching to a metal water bottle and reducing the amount of processed food you eat that comes packaged in plastic can be steps in the right direction.
