How Plastic Particles in Food Affect Liver Function: Study Sheds Light

New research presented at NUTRITION 2025, the annual meeting of the American Society for Nutrition held May 31-June 3 in Orlando, highlights potential health concerns related to microscopic plastic particles in food and beverages. The study, conducted in mice, found that ingestion of polystyrene nanoplastics may disrupt glucose metabolism and cause liver injury-raising concerns about possible health effects in humans.

As plastics break down over time, they form microplastics (less than 5 mm) and nanoplastics (less than 100 nanometers). These particles often enter the food chain, ending up in seafood and packaged foods. Research suggests people may consume between 40,000 and 50,000 plastic particles each year, with some estimates reaching as high as 10 million.

To simulate real-world exposure, the researchers administered a daily oral dose of polystyrene nanoparticles to 12-week-old male mice on a standard rodent diet. The dose—60 milligrams per kilogram of body weight—was chosen based on human exposure estimates and prior animal studies showing biological effects. Polystyrene is a common plastic found in food packaging.

“We can’t control for all the plastics the mice are exposed to,” said Amy Parkhurst, a doctoral candidate in the lab of Fawaz George Haj, PhD, at the University of California, Davis. “However, our study design allowed us to see dose-correlated changes since the nanoplastics-dosed group would have a higher exposure.”

The mice exposed to polystyrene showed systemic glucose intolerance and elevated levels of alanine aminotransferase, a marker for liver damage. Increased gut permeability and higher endotoxin levels were also observed—factors that contribute to liver dysfunction.

The team is now exploring how nanoplastics accumulate in different organs and plan to use advanced imaging techniques to map their metabolic impact.

Reference: https://nutrition.org/meeting/