Microplastic particles from takeaway containers and other everyday products can infiltrate the brain and trigger Alzheimer's-like symptoms within weeks, a new study suggests. Published in Environmental Research Communications, the research adds to growing evidence that tiny plastic particles are pervasive in the environment and routinely enter the human body through food, water and air.
The study focused on mice genetically modified to carry the APOE4 gene, a strong risk factor for Alzheimer's disease that makes people 3.5 times more likely to develop the condition than those with the APOE3 variant. Researchers exposed two groups of mice—one with APOE4 and one with APOE3—to micro- and nanoplastics in their drinking water for three weeks. The particles, found in Styrofoam containers and plastic cups, accumulated in the mice's organs, including the brain.
Cognitive tests revealed sex-dependent changes mirroring human Alzheimer's symptoms. Male APOE4 mice exposed to microplastics showed increased risk-taking behaviour, spending more time in open spaces, while female APOE4 mice were slower to recognise new objects, indicating memory decline. 'In human Alzheimer's patients, men tend to experience more changes in apathy; they care less. Women experience more changes in memory,' said study co-author Jaime Ross from the University of Rhode Island College of Pharmacy.
The findings suggest that environmental factors, such as microplastic exposure, may interact with genetic predisposition to accelerate cognitive decline. Dr Ross noted that lifestyle and environmental toxins are modifiable factors that could influence Alzheimer's risk. The researchers call for further investigation into the health impacts of micro- and nanoplastics, which are among the most common environmental toxins people encounter daily.
