Daijiworld Media Network - New Delhi

New Delhi, Jun 2: A new animal study suggests that tiny plastic particles commonly found in food and beverages could disrupt glucose metabolism and damage key organs like the liver.

Researchers from the University of California, Davis found that oral ingestion of polystyrene nanoplastics — the type often found in food packaging — led to glucose intolerance and signs of liver injury in mice.

“This confirms and extends what we know about the potential harm nanoplastics can cause,” said lead researcher Amy Parkhurst, a doctoral candidate at UC Davis.

Microplastics (less than 5 millimetres) and nanoplastics (less than 100 nanometres) can enter the human food chain through seafood and other foods. Previous estimates suggest an individual could ingest between 40,000 and 50,000 microplastic particles annually — with some figures reaching as high as 10 million particles a year.

For the study, the team exposed 12-week-old male mice to daily doses of polystyrene nanoparticles, mimicking human dietary exposure. The dose — 60 mg per kilogram of body weight — was based on human consumption estimates and earlier studies showing health impacts at similar levels.

“While we can’t control every source of plastic exposure in the lab, our design allowed us to see clear, dose-related changes,” Parkhurst noted.

The mice fed polystyrene nanoplastics showed significant glucose intolerance and higher levels of alanine aminotransferase, a marker of liver injury, compared to a control group. Additionally, researchers observed increased gut permeability and elevated endotoxin levels — both known contributors to liver dysfunction.

“These results highlight the need for further research to guide policies on micro- and nanoplastics,” Parkhurst said. “Robust scientific evidence is essential for shaping effective regulations.”

The study’s findings will be presented at the American Society for Nutrition’s flagship conference, NUTRITION 2025, currently underway in Orlando.