Microplastic Exposure and its Potential Role in Alzheimer’s Disease Risk in Genetically Susceptible Mice

Recent research highlights the troubling presence of microplastics in our environment and their potential impact on brain health. Micro- and nanoplastics, pervasive pollutants found in water, air, and food, can enter the human body and accumulate in various organs, including the brain. A groundbreaking study conducted by scientists at the University of Rhode Island examined this phenomenon using mice genetically modified to carry the APOE4 gene—a significant genetic risk factor for Alzheimer's disease. These mice, when exposed to microplastics through their drinking water for three weeks, showed increased presence of polystyrene particles in their brain tissue.

The study revealed sex-dependent behavioral changes in the mice. Male APOE4 mice exposed to microplastics tended to explore more in open spaces, indicating altered risk assessment behavior. Female APOE4 mice showed impaired ability to recognize novel objects, suggesting memory deficits. These behaviors mirror some symptoms seen in human Alzheimer's patients, where men often display increased apathy, and women tend to experience more pronounced memory loss.

The researchers utilized various behavioral tests, including an open-field and object recognition task, to assess cognitive function. The findings point to microplastics as potential environmental contributors to neurodegenerative processes, especially in individuals with genetic vulnerabilities like APOE4 carriers.

This research underscores the importance of understanding environmental toxins' role in cognitive decline and advocates for stricter regulation of plastic pollutants. The Microplastics Safety Act recently introduced in the U.S. aims to study these impacts further. As microplastics continue to infiltrate ecosystems, their possible link to brain health issues warrants urgent scientific and public health attention.

Source: https://medicalxpress.com/news/2025-09-microplastic-exposure-linked-alzheimer-disease.html