Junk Food Is Filling Our Brains With Microplastics, Raising Mental Health Risks, Scientists Warn

Gizmodo

20-05-2025

Scientists have found alarming amounts of microplastics in virtually everything, from sea turtles to testicles. But discovering a plastic spoon's worth of these pernicious particles inside human brains may be the most disturbing of all.
That recent finding prompted researchers to dig deeper into the health consequences of plastic accumulation in the brain. According to a new review study, published today in the journal Brain Medicine, microplastics may be the missing link in the relationship between ultra-processed foods and certain neurological disorders, such as depression and dementia.
'We're seeing converging evidence that should concern us all,' said lead author Nicholas Fabiano, a psychiatry resident at the University of Ottawa, in a statement.
'Ultra-processed foods now comprise more than 50% of energy intake in countries like the United States, and these foods contain significantly higher concentrations of microplastics than whole foods,' he added.
Indeed, multiple studies suggest that the more processed a food product is, the more plastic particles it is likely to contain. For example, one study found that chicken nuggets contain 30 times more microplastics per gram than chicken breasts. This may be due to the increased amount of plastic that ultra-processed foods are exposed to during processing and packaging, according to the Food Processing Forum.
Other recent studies have shown that microplastics can bypass the blood-brain barrier: a protective layer of cells surrounding the brain that keeps harmful substances out and locks beneficial chemicals in. The authors of the brain-spoon study, led by Alexander Nihart, Marcus Garcia, and Eliane El Hayek of the University of New Mexico, believe that microplastics infiltrate the blood-brain barrier by hitching a ride on fat molecules.
Once these particles get inside the brain, they induce oxidative stress that damages cells and increases the risk of neurological disorders, Fabiano's study states. He and his colleagues note that microplastics appear to have a particular impact on neurotransmitters that play a role in neuropsychiatric disorders such as depression and dementia. It's a big, bold claim that still needs to be verified with further research.
Interestingly, these harmful effects are strikingly similar to those triggered by ultra-processed foods, according to the researchers. A previous review found that people who consumed these foods had a significantly higher risk of depression, anxiety, and poor sleep. And multiple studies have linked this type of diet to an increased risk of dementia. As a result, Fabiano and his colleagues suggest that microplastics could be a hidden driver of neurological disorders associated with ultra-processed food consumption.
'This hypothesis is particularly compelling because we see remarkable overlap in biological mechanisms,' said co-author Wolfgang Marx, senior research fellow at Deakin University in Australia, in the statement. 'Ultra-processed foods have been linked to adverse mental health through inflammation, oxidative stress, epigenetics, mitochondrial dysfunction, and disruptions to neurotransmitter systems. Microplastics appear to operate through remarkably similar pathways,' he added.
So, that's the bad news. Here's the good news: a complementary study, also published in Brain Medicine today, provides the 'first evidence' to suggest that a well-established medical technique called extracorporeal apheresis could remove microplastics from the body.
This procedure involves extracting a patient's blood and running it through a machine that separates it into its parts: plasma and blood cells. Then, the plasma is filtered to remove any unwanted substances (like microplastics) and the clean plasma and blood cells are put back into the patient.
It's a relatively simple technique that's used all over the world for certain types of blood donation, therapeutic purposes, stem cell collection, and more. In tests with 21 patients, at least two rounds of extracorporeal apheresis with double-filtration successfully removed microplastics from their blood, according to the study.
'While we need to reduce our exposure to microplastics through better food choices and packaging alternatives, we also need research into how to remove these particles from the human body,' said lead-author Stefan Bornstein, a professor of cardiovascular and metabolic medicine at King's College London, in the statement.
'Our early findings suggest that apheresis might offer one possible pathway for microplastic removal, though much more research is needed,' he added.
Thus, as the global plastic crisis becomes more troubling by the day, exploring ways to protect the body from microplastics could help us clear our minds—literally.