Dementia is a condition that affects how people think, remember, and behave. It mostly happens in older adults, but younger people can also be affected. While many things are known to increase the risk of dementia—like age, genetics, and health conditions—new research suggests that the air we breathe could also play a role.
A recent study from Stockholm, Sweden, has found a link between air pollution and a higher risk of developing dementia. The study focused on tiny air particles known as PM2.5. These particles are so small that we can’t see them, but they can easily enter our bodies through our lungs. PM2.5 often comes from car exhaust, factory smoke, and other sources of pollution in cities.
Researchers followed more than 2,500 older adults living in urban areas for up to 12 years. During that time, 376 people developed dementia. The team collected information from interviews, blood tests, and surveys about the participants’ diets, physical activity, and other habits.
They wanted to see whether people who were exposed to more air pollution were more likely to develop dementia—and whether certain substances in the blood could explain the connection.
The two body substances they looked at are both important for brain health. One of them is found in common foods like meat, eggs, dairy, beans, and fish. The other is made by our own cells and can be turned into the first substance with help from vitamins. Together, these substances play a role in keeping brain cells healthy and supporting memory and clear thinking.
The study showed that people who developed dementia were exposed to slightly higher levels of PM2.5 compared to those who didn’t. These same individuals also had higher levels of one body substance and lower levels of the other.
After considering other factors—like age, smoking, gender, and education—the researchers found that even a small rise in PM2.5 exposure was linked to a 70% increase in the risk of developing dementia.
Even more interesting, about half of that increased risk seemed to be related to the levels of those two body substances. This suggests that air pollution might affect our brain not just directly, but also by changing the balance of certain nutrients or chemicals in the body.
Although the exact way that air pollution affects the brain is still not fully known, this study gives researchers a new path to explore. It also shows how deeply connected our environment is to our health—not just our lungs or heart, but our brain as well.
While this is still early research, it points to the importance of protecting air quality. It also shows how our diet can support brain health, especially if it helps maintain the right balance of important substances in the body.
Other studies have also suggested that regular exercise, a healthy diet (like the Mediterranean diet), and staying socially and mentally active can help protect the brain and slow down cognitive decline.
This new research, published in the journal Neurology, reminds us that staying healthy isn’t only about what we eat or how much we move. It’s also about the world we live in. Clean air, good nutrition, and healthy habits all work together to keep our bodies—and our brains—working their best.
If you care about dementia, please read studies about Vitamin B9 deficiency linked to higher dementia risk, and flavonoid-rich foods could help prevent dementia.
For more information about brain health, please see recent studies that cranberries could help boost memory, and how alcohol, coffee and tea intake influence cognitive decline.
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