A head full of microplastics, you shouldn’t think about it, but it really seems to be. There is much more plastic in our brain than in other organs and it accumulates: in eight years the amount of plastic in investigated brain increased by 50 percent.

Microplastics have already been found in just about our entire body, from your liver and your lungs to the testicles and the placenta, but nowhere has it been found such a high concentration as in the brain, researchers discovered the University of New Mexico Health Sciences (UNM). There are some grams of microplastics in our brain. “It corresponds to a standard plastic torch,” said lead researcher Matthew Campen at CNN. “Nowadays, half a percent of our brains consists of plastic.”

And those microplastics therefore accumulate at a rapid pace. A reflection of the increasing amount of plastic waste on earth, according to the toxicologist, who calls his results alarmingly. “This really changes everything. It makes it so much more personal. ” Moreover, he discovered that much of the plastic is much smaller than expected. The plastic particles are only about two to three times as large as viruses.

Twelve different polymers
For The new study used his brains of the deceased. The older brain tissue dates from 2016 on average and was compared with tissue from 2024. All samples were collected from the frontal cortex, the brain area above and behind the eyes.

Twelve different polymers were found, the most common polyethylene, which is widely used for packaging, bottles and cups. The researchers also found clusters of sharp plastic particles of 200 nanometers or less – not much larger than viruses. They are small enough to pass the blood-brain barrier, although Campen says it is unclear how the particles actually end up in the brain.

Microplastics and dementia
It is also unclear what effects plastic has. The physical properties of these particles can sometimes be the real problem, in contrast to a kind of chemical toxicity. “We are starting to think that these plastics might hinder blood flow in the capillaries,” said Campen. “It is possible that these nanom materials disrupt the connections between axons in the brain. They could also be a breeding ground for the accumulation of proteins involved in dementia. We just don’t know. ” But that there is a connection with dementia was clear from the research: brain tissue of people who were diagnosed with dementia had up to ten times as much plastic in their brains than others. Although it has not been said that it is a causal relationship. It is also possible that microplastics accumulate more due to the disease process itself.

Eat less meat
Campen suspects that most microplastics end up in our body through food, especially meat. “The way we spray fields with water contaminated with plastic suggests that the plastics accumulate there. We feed it to our cattle. We take the manure with us and bring it back to the field, so this creates a plastic cycle. ” The team has also found high concentrations of plastic in meat from the supermarket.

In the meantime, the global production of plastic continues unabated, but even if it is stopped tomorrow, it is a ticking time bomb. Because it takes decades for existing polymers to fare into microscopically small particles, the concentrations of micro and nanoplastics in the environment will increase for years.

Alarm
Campen, who often quotes the saying of toxicologists: “Dosis makes the poison”, Says that the new results are a reason to raise an alarm about a worldwide threat to human health. However, he acknowledges that consumers often shrug their shoulders about microplastics: after all, you can’t do much about it if it is in your drinking water. But the new findings could change that. “I still have to come across the first person who says: there is a lot of plastic in my brain and I think that’s fine.”