Study Discovers Microplastics in Brain Tissue

The accumulation of microplastics in vital human organs like the brain, liver, and kidney is increasing, according to a new study.

Micro- and nano plastics (MTPs) are tiny particles ranging from 500 micrometers in diameter down to 1 nanometer, resulting from the breakdown of plastic. They have been found all over the world, from Antarctic snow to the bottom of the Atlantic Ocean.

MPT accumulation in human bodies has been a subject of concern, although the extent to which microplastics cause harm is unclear. Previous research has linked exposure to MNP with increased inflammation and elevated risk of cardiovascular events.

A new study, which is still being peer-reviewed and was published by the National Institutes of Health, looked for 12 polymers — types of microplastics — in human samples collected in 2016 and 2024.

The predominant microplastic was polyethylene, used in bottles, water tanks, clear food wraps, and plastic bags, among other household items.

Researchers say the parallels between increasing MNP concentrations in the brain, the rising environmental presence of microplastics, and growing rates of dementia add urgency to understanding the impacts of MNP on human health.

Why are microplastics dangerous?

While the new study's findings have yet to be peer-reviewed, increasing evidence shows that microplastics infiltrate various human organs.

A recent study published in the Journal of Hazardous Materials found microplastics for the first time in human bone marrow. Another study from 2024 revealed the prevalence of microplastics in human and canine testicles.

A 2023 review of studies suggests that exposure to microplastic may cause numerous health problems, including the following:

• When ingested, microplastics can lead to inflammation in the gastrointestinal tract and changes in the intestinal microbiome, causing symptoms like abdominal pain, bloating, and changes in bowel habits.
• When inhaled, microplastics can cause oxidative stress in the airways and lungs, leading to symptoms like coughing, sneezing, and shortness of breath due to inflammation and damage. Moreover, a low blood oxygen concentration can cause fatigue and dizziness.
• Microplastics may disrupt endocrine systems, leading to various endocrine disorders, including metabolic, developmental, and reproductive disorders.
• In mice studies, nanoplastic accumulation in the central nervous system caused neuronal damage. Moreover, exposure to microplastics resulted in cognitive dysfunction.

A 2024 study discovered that the presence of MNPs within the atheroma, a fatty material that builds up inside the arteries, raised the risk of myocardial infarction, stroke, or death from any cause.

While the presence of microplastics worldwide is only increasing, the study authors call for more research on their toxicity and related diseases.