Alzheimer's Risk Factors: Air Pollutants

Lane Simonian

This is the most recent study on the link between air pollutants and Alzheimer's disease:

Increased risk of Alzheimer's disease due to exposure to polycyclic aromatic hydrocarbons, suggests study

https://phys.org/news/2023-04-alzheimer-disease-due-exposure-polycyclic.html

One of the routes here is a familiar one: the overactivation of g protein-coupled receptors:

"PAHs may bind and activate cellular receptors including the AhR [aryl hydrocarbon receptor] and the G protein-coupled receptor (GPCR) β2-adrenergic receptor." 

The most extensive studies on the effects on air pollutants on cognitive function have been done in Mexico City. Children exposed to very high level of pollutants in the city have several of the "hallmarks" of Alzheimer's disease include diffuse amyloid plaques and tau tangles. When give dark cocoa--an antioxidant--their cognitive function improved somewhat.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749371/

And here is one more familiar finding, air pollutants like all other risk factors for Alzheimer's disease increase the production of oxidants: hydrogen peroxide (early on) and peroxynitrite.

Chemical modification of pro-inflammatory proteins by peroxynitrite increases activation of TLR4 and NF-κB: Implications for the health effects of air pollution and oxidative stress

These findings suggest that environmental pollutants and related ROS/RNS [Reactive Oxygen Species/Reactive Nitrogen Species] may play a role in promoting acute and chronic inflammatory disorders by structurally modifying the body's own DAMPs [damage associated molecular patterns]. This may have important consequences for chronic neurodegenerative, cardiovascular or gastrointestinal diseases that are prevalent in modern societies, and calls for action, to improve air quality...

https://pubmed.ncbi.nlm.nih.gov/32739154/

It is unlikely that all of the damage that oxidative stress does to the brain can be reversed but some of it can with the use of certain antioxidants.