To summarize the epidemiological and mechanistic evidence linking environmental pollutants to Alzheimer's disease (AD) risk and pathogenesis, elucidate shared biological mechanisms, and propose a comprehensive prevention framework that emphasizes immediate action.
Approach:
Key Findings:
Alzheimer’s disease accounts for 60–70% of dementia cases, with a projected increase in prevalence, reaching 13.8 million cases in the U.S. by 2060.
14 modifiable risk factors for AD include air pollution, which is a significant contributor to dementia cases, accounting for approximately 45% of global dementia cases.
Environmental pollutants can lead to neuropathological changes consistent with early AD features, potentially beginning in childhood, as evidenced by studies in heavily polluted areas.
The exposome concept highlights cumulative environmental exposures that may accelerate AD onset, necessitating a focus on long-term exposure effects.
Evidence for neurotoxic potential varies among pollutants, with PM2.5 showing the strongest association with AD, supported by large-scale studies.
Interpretation:
The review emphasizes the critical importance of addressing environmental pollution as a modifiable risk factor for Alzheimer's disease, particularly in high-exposure populations, to mitigate future cases.
Limitations:
The strength of evidence varies across pollutant classes and study designs, with some pollutants showing more robust associations than others.
Some associations remain provisional and require further confirmation through prospective studies, particularly for emerging pollutants.
Conclusion:
A comprehensive understanding of the relationship between environmental pollutants and Alzheimer's disease is crucial for developing effective prevention strategies, and immediate action is necessary to address these risks.
