Microplastics are miniscule particles of plastic less than 5 millimeters in size — as small or smaller than a grain of sand. How much damage can something this tiny do? Plenty, it turns out, especially when it comes to our bodies.

Last month the journal Nature published a study that found high levels of microplastics present in the brains of deceased people. Now Canadian researchers have authored a peer-reviewed "commentary" in Brain Medicine that unpacks those findings and lays out why they are so significant. The commentary also offers some ideas for ways one can reduce their exposure to microplastics.

“Avoiding plastic food storage and using glass or stainless steel alternatives is a small, but meaningful step in limiting exposure.”

We know these tiny plastic particles are everywhere in our oceans and earth. Now we know these mini particles are present in human brain tissues — at concentrations 7 to 30 times higher than in other organs.

The microplastics and nanoplastics (NPs) are primarily made up of polyethylene.

The study also showed that the accumulation of microplastics in brains was higher among those who died in 2024 than those who died in 2016, indicating the problem and its effect on health are growing.

Microplastic levels were also higher among people who had been diagnosed with dementia, suggesting a likely connection between the numbers of these tiny particles in our brains and the loss of memory, language, problem solving and other thinking abilities seen as people age.

Plastic particles smaller than 200 nanometers are prominent in our cerebrovascular walls and in our immune cells, scientists found. They are so tiny they have the potential to cross our blood-brain barrier, further raising a red flag about their connection to worsening neurological conditions, especially since levels of microplastics were 3 to 5 times higher in people who had been diagnosed with dementia.

“This dramatic increase in brain microplastic concentrations over just eight years, from 2016 to 2024, is particularly alarming,” the lead author of the commentary, Dr. Nicholas Fabiano from the University of Ottawa's Department of Psychiatry, noted in a press release. “This rise mirrors the exponential increase we're seeing in environmental microplastic levels.”

Plastic particles are present in human brain tissues at concentrations 7 to 30 times higher than in other organs.

What can we do to protect our bodies and brains from filling with microplastics and nano-sized particles? The authors of the commentary offered some strategies:

  • Switch from bottled to filtered tap water and you'll lessen your exposure by almost 90 percent. Just by taking this step, you can reduce your microplastic intake from 90,000 to 4,000 particles per year. “Bottled water alone can expose people to nearly as many microplastic particles annually as all ingested and inhaled sources combined,” said Dr. Branon Luu, an Internal Medicine Resident at the University of Toronto.
  • Don't use plastic tea bags. They release millions of micro- and nano-sized particles. The best alternative is to use loose tea leaves.
  • Avoid heating your prepared meals in the microwave. “Heating food in plastic containers — especially in the microwave — can release substantial amounts of microplastics and nanoplastics,” Luu says. “Avoiding plastic food storage and using glass or stainless steel alternatives is a small, but meaningful step in limiting exposure.”
  • Sweating may also help eliminate certain plastic-derived compounds from our bodies, scientists suggest. Think about taking frequent saunas or allow yourself to sweat from exertion.
  • Other possible ways to minimize exposure include: avoiding canned foods with plastic liners; shopping for clothes made of natural fibers; using wood or bamboo cutting boards; and ordering drinks in real mugs in cafes.

For more ways you can make an impact on this issue, visit the Plastic Pollution Coalition.