The role of microplastics exposure in Alzheimer’s and Parkinson’s disease

In recent times, both in vitro and in vivo studies have demonstrated toxicological and pathological evidence of microplastic exposure in neurological dysfunction and diseases. The mechanistic linkage of microplastics and nanoplastic exposure in Alzheimer’s disease and Parkinson’s disease—two of the most common neurodegenerative diseases in humans have not been explored. This gap in knowledge forms the basis of this review. Moreover, the global population keeps ‘consuming’ plastics through the skin, nostrils and mouth—which ultimately could result in intoxication, pathologies and contribute to the pathogenesis of Alzheimer’s and Parkinson’s. This narration examined the relationship between the risk of encountering microplastics and nanoplastics and the possible mechanisms of neurotoxicity and neurodegeneration, including oxidative stress, neuroinflammation, disruption of the blood–brain barrier, and protein clustering/ aggregation in both animal models and humans. Though strong linkage was found between microplastic exposure and the neurodegenerative diseases, further studies are required in this area—while public health scientist and policy makers are called to act to curb the global environmental challenge of plastic pollution.