Mouse study suggests that starch-based microplastics may harm health

Starch-based plastics, which are derived from treated starch from plants, may not be as safe or environmentally benign as previously assumed. Composed mainly of starch and typically blended with other biobased polymers such as polylactic acid (PLA), starch-based plastics were hailed as a green alternative to conventional plastics and are now widely used in everyday products like food packaging and disposable cutlery. These natural polymers readily degrade in the environment, aided by the action of microbes in the soil, but evidence increasingly suggests that this breakdown process may take longer than originally predicted. For Yongfeng Deng, a geomaterials researcher at Southeast University in China, the most worrying consequence of this incomplete breakdown is the accumulation of biomicroplastics in environmental media and, ultimately, the food chain. While many studies have examined the health implications of ingesting petroleum-derived microplastics, none have looked at the long-term health effects on a living organism ingesting starch-based microplastics. To help elucidate the safety of these ecoplastics, Deng and his team used a mouse model to simulate long-term exposure to varying doses of starch-based microplastics. (J. Agric. Food Chem. 2025, DOI: 10.1021/acs.jafc.4c10855) They incorporated various concentrations of starch-based microplastics into the animals’ food, scaled to reflect typical human exposure; after 3 months, they euthanized the mice to probe the impacts of no, low, and high consumption of microplastics.Organ-sample analysis revealed system-wide physiological changes, including reduced ovary size, liver damage and inflammation, and impaired colon function. “Starch-based microplastics exhibit widespread harm, potentially affecting multiple tissues and functions,” Deng