Breathing polluted air for many years may hurt brain health in older adults, according to a new study from researchers at University College London (UCL).
The study found that people over 65 who lived in areas with high levels of air pollution performed worse on tests of memory and thinking, especially those related to language skills.
The research was published in The Journals of Gerontology, Series A, and focused on two major types of air pollution: nitrogen dioxide (NO2) and fine particulate matter (PM2.5).
NO2 mainly comes from vehicle exhaust, power plants, and machinery.
PM2.5 comes from burning fuels like gasoline, oil, wood, and coal, and contains tiny particles that can travel deep into the lungs and even enter the bloodstream.
The researchers studied data from 1,127 people aged 65 and older in England who took part in the English Longitudinal Study of Ageing in 2018.
They looked at how much air pollution these people had been exposed to between 2008 and 2017 and then tested their brain function. The tests measured memory, language skills, and other thinking abilities such as planning and problem-solving.
Participants completed a range of well-known memory and thinking tasks, such as remembering stories, drawing shapes, counting backward, and recalling words.
The results showed that people living in the most polluted areas scored lower on these cognitive tests compared to those living in areas with average pollution levels.
The strongest link was found in language skills—people in high-pollution areas were more likely to fall into the bottom third of the scores.
The study also found that not all pollution sources have the same effect. Pollutants from factories, home heating, and burning fuels like coal and oil were more strongly linked to worse performance in language tasks. This suggests that some sources of pollution may be especially harmful to the parts of the brain that help us understand and use language.
Although the study didn’t explore exactly how air pollution harms the brain, researchers believe that certain pollutants may affect the temporal lobe, the part of the brain that supports language and memory. More research is needed to understand the biological reasons behind these findings.
Lead researcher Dr. Giorgio Di Gessa said the study shows air pollution doesn’t just affect the lungs and heart—it also damages brain health over time. Professor Paola Zaninotto, co-author of the study, added that their long-term data offers strong evidence that long exposure to pollution can harm the brain.
The researchers are now calling on policymakers to improve air quality standards, especially in highly polluted areas, to protect public health as the population continues to age.
While the study had some limits—it only covered 10 years and used average pollution levels—it still provides valuable insight into the long-term risks of air pollution on the brain.
If you care about brain health, please read studies about inflammation that may actually slow down cognitive decline in older people, and low vitamin D may speed up cognitive decline.
For more information about brain health, please see recent studies about common exercises that could protect against cognitive decline, and results showing that this MIND diet may protect your cognitive function, prevent dementia.
