Poor Air Quality Fogs Up Our Brains: Can NSAIDs Prevent Cognitive Decline Caused By Pollution?
In today’s world, we’re constantly being exposed to different kinds of air pollution, whether it be from smog, traffic, smoke from naturally occurring fires, cigarettes and cigars, or charcoal grills. Not only do these particulates harm our lungs, but, as it turns out, they can also negatively affect our cognitive abilities.
Exposure to air pollution, even over just a few weeks, can impede mental performance, according to a new study published in the journal Nature Aging. However, researchers at Columbia University Mailman School of Public Health found that these adverse effects were lessened in people taking nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin, ibuprofen, and naproxen. The study is among the first to explore short-term air pollution exposures and the use of NSAIDs to mitigate their effects.
Pollution can plummet mental performance
As more people reach their 70s and beyond, researchers have become interested in “successful aging”. This concept relates to reaching an advanced age without any major disease or disability. And, a key parameter to consider when evaluating the quality of life in older age is the preservation of cognitive function. There are several contributors to cognitive decline, in addition to the neurodegenerative diseases that lead to dementia, such as Alzheimer’s disease.
One such contributor is air pollution. Exposure to fine particulate matter is a well-documented driver of cognitive decline. Studies show that chronic exposure to particulate matter with a diameter of fewer than 2.5 micrometers, which is about 30 times smaller than the width of a piece of hair, leads to long-lasting effects like reduced brain volume, decreased cognition, and the development of dementia (1).
Other research points to older women being especially at risk (2). Environmental studies are concerning as well, as a US study of older adults living in cities with high concentrations of particulate matter found that these adults had a greater error rate in working memory and orientation tests than those exposed to lower concentrations (3).
Environmental measures aren’t enough
Alarmingly, the effects of air quality on cognition are not limited to what’s seen in older adults. Black carbon from vehicular traffic is a major component of particulate matter and has been associated with poor cognition in children and younger adults (4). Over the past few decades, large-scale efforts and emission control policies have lowered average particulate matter levels.
However, scientists are not sure if these measures will help moderate some of the adverse health effects associated with air pollution. Lead author Dr. Andrea Baccarelli said, “Despite regulations on emissions, short-term spikes in air pollution remain frequent and have the potential to impair health, including at levels below that usually considered hazardous."
It’s also hard to evaluate the impact that these measures may have because even in regions where particulate matter levels have seen reductions, there are still days where pollution may spike. Researchers believe that exposure to short-term, high-pollution environments may still add to the risk for health consequences.
Scientists believe that pollution causes declines in cognition because particles that are inhaled trigger an inflammatory response in brain tissues. Over time, this chronic neuroinflammation disrupts the proper flow of blood to different areas of the brain and impairs the proper functioning of the lining of blood vessels in the brain.
For this reason, scientists have proposed different treatments to counter the adverse effects of air pollution. As it turns out, the answer may lie in the family of over-the-counter drugs called NSAIDs.
Limiting inflammation with NSAIDS lessens pollution’s toxic effects
That’s why the group of researchers from Columbia University Mailman School of Public Health recently examined the effects of NSAIDs on the neuroinflammation caused by pollution (5). Gao and colleagues wanted to identify a mitigating treatment for damage caused by short-term spikes in pollution.
To do so, the researchers examined the effects of black carbon and fine particulate matter on a group of 954 men who lived in or around the city of Boston. They monitored air quality for several days to measure levels of pollution while the study was taking place, and the participants were asked to complete a series of questionnaires and tests to evaluate their cognition.
Gao and colleagues then compared the pollution rates to the results from the cognition tests. They took into consideration the average pollution rates and the rates from when there was an increase in fine particulate matter or higher levels of black carbon and kept track of NSAID use among the participants.
Their results showed that after 28 days of high exposure to particulate matter, the participants’ performance on cognitive tests declined significantly. However, the use of NSAIDs seemed to offer protection against the effects of spikes in air pollution. Men who took NSAIDs during the periods of high exposure had a lower impact on their cognitive scores than those who did not.
What’s next for NSAIDs and air pollution?
This study elucidates the short-term impacts of air pollution on cognition and warrants further investigations on the modifying effects of NSAIDs. Researchers expect to better understand pollution’s effects on cognitive function by studying the chemical effects of pollution components on brain structures.
Although how NSAIDs confer protection is not completely understood, researchers speculate that these medications may moderate neuroinflammation and improve detrimental changes to blood flow in the brain caused by pollution. The protective role of NSAIDs against pollution will be tested in future trials as well.
- Power MC, Adar SD, Yanosky JD, Weuve J. Exposure to air pollution as a potential contributor to cognitive function, cognitive decline, brain imaging, and dementia: A systematic review of epidemiologic research. Neurotoxicology. 2016;56:235-253. doi:10.1016/j.neuro.2016.06.004
- Cacciottolo M, Wang X, Driscoll I, et al. Particulate air pollutants, APOE alleles and their contributions to cognitive impairment in older women and to amyloidogenesis in experimental models. Transl Psychiatry. 2017;7(1):e1022. Published 2017 Jan 31. doi:10.1038/tp.2016.280
- Ailshire JA, Clarke P. Fine particulate matter air pollution and cognitive function among U.S. older adults. J Gerontol B Psychol Sci Soc Sci. 2015;70(2):322-328. doi:10.1093/geronb/gbu064
- Suglia SF, Gryparis A, Wright RO, Schwartz J, Wright RJ. Association of black carbon with cognition among children in a prospective birth cohort study. Am J Epidemiol. 2008;167(3):280-286. doi:10.1093/aje/kwm308
- Gao, X., Coull, B., Lin, X. et al. Short-term air pollution, cognitive performance and nonsteroidal anti-inflammatory drug use in the Veterans Affairs Normative Aging Study. Nat Aging (2021). https://doi.org/10.1038/s43587-021-00060-4