New Delhi– Microscopic plastic particles commonly found in food and beverages may disrupt glucose metabolism and damage vital organs such as the liver, according to a new animal study that highlights growing concerns over human exposure to microplastics and nanoplastics.
The research, conducted at the University of California, Davis, examined how ingesting polystyrene nanoplastics—a type of plastic widely used in food packaging—can negatively affect liver health and metabolic function.
“Oral ingestion of polystyrene nanoplastics contributes to glucose intolerance and signs of liver injury,” said Amy Parkhurst, a doctoral candidate and lead researcher on the study. “Our findings confirm and expand upon recent reports about the harmful effects of nanoplastics in animal models.”
Microplastics (less than 5 millimeters in size) and nanoplastics (smaller than 100 nanometers) are increasingly detected in the food chain, particularly in seafood, packaged goods, and bottled beverages. Prior estimates suggest that humans may consume between 40,000 and 50,000 plastic particles per year, with some studies suggesting exposure could reach up to 10 million particles annually.
To simulate real-world exposure, researchers administered a daily oral dose of polystyrene nanoplastics—60 mg per kilogram of body weight—to 12-week-old male mice over a sustained period. The dose was chosen based on previously reported human exposure levels and past studies showing adverse health effects in mice.
While acknowledging that environmental contamination could not be entirely controlled, Parkhurst noted that the study design allowed for clear dose-dependent results. “The nanoplastics-exposed group showed more pronounced physiological changes, making the findings statistically significant,” she explained.
Compared to the control group, the mice exposed to nanoplastics developed systemic glucose intolerance and showed elevated levels of alanine aminotransferase (ALT)—a key marker of liver damage. Researchers also observed increased gut permeability and elevated endotoxin levels, both of which contribute to inflammation and liver dysfunction.
“These results underscore the need for more rigorous research to guide public health policies and regulations regarding microplastic and nanoplastic contamination in the food supply,” said Parkhurst. “Scientific evidence like this plays a vital role in shaping monitoring efforts and informing safety standards.”
The findings will be presented at NUTRITION 2025, the flagship annual conference of the American Society for Nutrition, currently underway in Orlando, Florida. (Source: IANS)
