Study Links Microplastics in Food to Early Signs of Liver Damage

By now, you're probably aware that microplastics are everywhere. According to an estimate by the World Economic Forum, the average person ingests between 78,000 and 211,000 microplastic particles each year. We know we're consuming them, but what's less understood is how these microscopic particles affect our bodies. However, as more scientific research emerges, we're learning that those effects aren't good. 

In June, researchers shared the results of a new animal study suggesting that microplastics ingested through food and beverages can damage organs, such as the liver, by affecting how people metabolize glucose.

“With the growing concern around micro- and nanoplastic exposure, we wanted to evaluate the impact of this exposure on health,” Amy Parkhurst, a doctoral candidate working in the laboratory at the University of California, Davis, shared in a statement about her work, which she presented at the Nutrition 2025 meeting held from May 31 to June 3. “Our observations that oral ingestion of polystyrene nanoplastics contributes to glucose intolerance and signs of liver injury, confirm and extend what has been recently reported on the effects of nanoplastics in animal models.”

According to Eureka Alert, Parkhurst and the other researchers created a life-like model of oral consumption to simulate how humans might be exposed to nanoparticles through food and drink in everyday situations. To do this, they gave 12-week-old mice a standard rodent diet along with a daily oral dose of 60 milligrams per kilogram of body weight of polystyrene nanoparticles, which are common in food packaging. The researchers stated that this is based on the same exposure levels experienced by humans. 

“We can’t control for all the plastics the mice are exposed to,” Parkhurst added. “However, our study design allowed us to see dose-correlated changes since the nanoplastics-dosed group would have a higher exposure.”

The team found that mice consuming the nanoplastics exhibited “systemic glucose intolerance and elevated alanine aminotransferase, which indicates liver injury.” The researchers also observed an increase in gut permeability, which can contribute to further liver problems.

“Our findings warrant further studies to help inform policy around micro and nano plastics,” Parkhurst said. “Robust scientific evidence plays a key role in shaping monitoring efforts and guiding regulations.”

This new report adds to the growing body of evidence about microplastics and where we might be unintentionally consuming them. In January, researchers shared their findings in the journal Frontiers in Toxicology, showing that popular fish caught off the Oregon coast, including black rockfish, lingcod, Chinook salmon, Pacific herring, Pacific lamprey, and pink shrimp, all contained measurable amounts of microplastics. 

Also in January, researchers from the Autonomous University of Barcelona in Spain published a new study showing that individual tea bags steeped in boiling water can release massive amounts of micro- and nanoplastic particles. The team found that when brewing tea, “polypropylene releases approximately 1.2 billion particles per milliliter, with an average size of 136.7 nanometers; cellulose releases about 135 million particles per milliliter, with an average size of 244 nanometers; while nylon-6 releases 8.18 million particles per milliliter, with an average size of 138.4 nanometers.”

And in late 2024, researchers shared their study findings about microplastics in plastic soda bottles, revealing that the more you open and close a bottle, the more microplastics the bottle and its cap release, which you subsequently drink. 

However, not all the research is doom and gloom. In April, researchers published the findings of a study that found that colorful fruits and vegetables may combat the negative effects of microplastics in the body. So, yes, it turns out that the “an apple a day” adage is a good one.