Ubiquitous and almost invisible, the tiny shards of plastic that are entering the human body through the food we eat could be damaging our brains in multiple ways, experts fear.
A team of scientists have identified “five main pathways” along which so-called microplastics – shed from items such as plastic bottles, containers and cutting boards – may harm the brain and could be accelerating the development of neurodegenerative diseases.
In a paper published December (2025) in the science journal Molecular and Cellular Biochemistry, researchers at the University of Technology Sydney (UTS) in Australia and Auburn University in Alabama, United States, warn that microplastics disrupt immune cell activity, impair mitochondria and damage neurons.
“Microplastics actually weaken the blood-brain barrier, making it leaky.
“Once that happens, immune cells and inflammatory molecules are activated, which then causes even more damage to the barrier’s cells,” says UTS drug delivery researcher Assoc Prof Dr Kamal Dua.
Although the human body expels most of the dinner plate-sized amount of plastic ingested each year, small amounts can accumulate in organs, he says.
Because the body reacts to microplastics as “foreign intruders”, immune cells in the brain go on the offensive.
But, according to Assoc Prof Dua, “when the brain is stressed by factors like toxins or environmental pollutants, this also causes oxidative stress”.
One of the chief concerns around microplastics remains unproven: that they could be contributing to Alzheimer’s disease by triggering increased build-ups of beta-amyloid and tau proteins while having a similar impact on Parkinson’s disease onset by damaging neurons.
However, the “persistent use of plastics in daily life” means there is “an urgent need for further research” into how they lead to “neurological outcomes”, the researchers concluded in their paper, calling for efforts to clarify microplastics’ role in Alzheimer’s and Parkinson’s.
In advice to consumers, study co-author and UTS senior researcher Dr Keshav Raj Paudel says: “Steer clear of plastic containers and plastic cutting boards, don’t use the dryer, choose natural fibres instead of synthetic ones, and eat less processed and packaged foods.” – dpa
