Brain samples have consistently higher levels of microplastics than liver or kidney samples
Levels of microplastics in the human brain have increased by 50% in the last eight years, according to a pioneering new study.
Researchers looked at autopsy samples taken in Albuquerque, New Mexico, between 2016 and 2024. They compared microplastic levels between different organs—the brain, liver and kidneys—and also compared levels in these organs over time.
The found that the brain samples contained significantly more microplastics than the kidney or liver samples. There noted a significantly larger amount of one plastic in particular, polyethylene, in the brain samples. Polyethylene is used in plastic bags, bottles and other containers.
Even more worryingly, the researchers noted that levels of microplastics increased over time. Concentrations in the brain samples rose by 50% in the last eight years.
The researchers believe the results may be explained by the fact that the liver and kidneys are “front line” organs for the removal of harmful substances from the body, so they are better equipped than the brain to dispose of microplastics.
Plastics are lipophilic—meaning they are attracted to fatty tissues—and the brain has the second highest lipid content of any organ in the body, besides adipose tissue itself, as well as a massive, extensive bloody supply to carry microplastics to it.
More than nine billion tons of plastic are estimated to have been produced between 1950 and 2017, with over half of that total having been produced since 2004. The vast majority of plastic ends up in the environment in one form or another, where it breaks down, through weathering, exposure to UV light and organisms of all kinds, into smaller and smaller pieces—microplastics and their even trickier brethren, nanoplastics. These are “secondary” microplastics, but there’s a whole class of “primary” microplastics which are small by design, like so-called “microbeads” used in cosmetics. Within our homes, microplastics are mainly produced when synthetic fibres from clothes, furnishings and carpets are shed. They accumulate in large quantities in dust and float around in the air, which we then inhale.
Microplastics have become a source of major health concern in recent years as the extent of human and animal exposure to them has become clearer. These minute pieces of plastic, often invisible to the naked eye, have been linked to virtually every major chronic disease of the modern age, from obesity and gut conditions like IBS, to cancer and neurodegenerative diseases like Alzheimer’s and Parkinson’s.
Microplastics have also been implicated in the worldwide fertility crisis that could see humans unable to reproduce by natural means as early as 2050. According to expert Professor Shanna Swan, by 2050 the median man will have a sperm count of zero, meaning one half of all men will produce no sperm whatsoever, and the other half will produce so few they might as well produce none.
If you want to know more about microplastics, and how you can protect yourself and your loved ones from the, read our longform primer on the subject.
