A new U.S. study found that microplastic accumulation in the human brain has increased by nearly 50% in the last eight years, raising concerns about the long-term health effects of increased plastic exposure.
The study, published in Nature Medicine in February under the title "Bioaccumulation of microplastics in decedent human brains," examined tissue samples from 30 people's brains, livers and kidneys across the U.S. Researchers measured both microplastics and nanoplastics and the brain had the highest concentrations, nearly 10 times higher than other organs.
In the brain's frontal lobe alone, researchers discovered approximately 4,917 micrograms of plastic per gram of tissue, up from 3,345 micrograms in 2016. Experts estimate that this is roughly equivalent to the plastic content of a standard plastic bag.
Plastic levels increased in all organs compared to previous data, with the liver increasing from 433 to 500 micrograms, the kidneys from 404 to 480 micrograms and the brain from 3,345 to 4,917 micrograms. These findings indicate that plastic particles are increasingly capable of infiltrating human tissue, with the brain being particularly vulnerable.
Professor Mustafa Ozdogan, an oncology expert and president of Türkiye's Hereditary Cancers Association, told Anadolu Agency (AA) that the brain's high fat content and constant blood circulation make it more susceptible to plastic buildup. He explained that particles as small as one nanometer can now pass through the blood-brain barrier, which was previously thought to be one of the body's most secure defenses.
According to Ozdogan, the amount of plastic found in the brain's frontal region was nearly 2 grams, which is roughly equivalent to a plastic bag. The particles were mostly colorless or transparent and varied in shape, including round, threadlike and angular. These forms allow plastic to enter the body via a variety of pathways, including food, air and water.
The study identified polyethylene as the most common plastic found in brain tissue. This material is widely used in products such as plastic bags, water bottles, food packaging and synthetic textiles. Ozdogan added that everyday items like disposable utensils, cosmetics and clothing all contribute to plastic exposure.
He warned that these particles could be linked to a variety of serious health conditions, including cardiovascular disease, stroke, dementia, Alzheimer's, digestive problems and hormone-related disorders. He explained that microplastics trigger inflammation and toxic stress in blood vessels and brain tissue, hastening the progression of these diseases.
Ozdogan said elderly people and dementia patients are at the highest risk of microplastic exposure. The blood-brain barrier weakens as we age, allowing more particles to enter. People with compromised immune systems have a lower ability to eliminate these substances from their bodies.
He added that the health impact of microplastics is more than just volume. Many of these particles contain endocrine-disrupting chemicals that interfere with hormonal systems. This has the potential to impact future generations' fertility, development and reproductive capacity.
Lifestyle choices directly influence exposure, Ozdogan said, citing studies showing that people who drink only bottled water may ingest up to 90,000 microplastic particles annually, while those who drink tap water consume about 4,000.
He advised using glass or stainless-steel bottles, avoiding plastic containers when heating food, opting for glass food storage, using cloth shopping bags and choosing natural-fiber clothing. However, he stressed that individual efforts are not enough.
"Real solutions to plastic pollution require societal awareness and strong legislation,” he said. He called for restrictions on single-use plastics, stricter food packaging regulations, improved water safety infrastructure, and public education to reduce overall plastic contamination.
