Dementia is a brain condition that causes problems with memory, thinking, and behavior. It mostly affects older adults, but younger people can also develop it.
A new study has found a possible link between air pollution, certain substances in the body, and the risk of developing dementia.
Air pollution is a major concern in many parts of the world. It’s already known to harm the lungs and heart. Now, scientists are finding more evidence that it may also damage the brain. The study, published in the journal Neurology, looked at whether tiny air particles known as PM2.5 could raise the risk of dementia.
PM2.5 are small dust-like particles in the air that are too tiny to see. They mainly come from car exhaust, factory smoke, and burning fuel. Because they are so small, they can get deep into the body when we breathe them in.
In this study, researchers focused on two substances in the blood—let’s call them “body helpers.” One of these comes from foods like meat, fish, dairy, beans, and eggs, and is important for healthy brain function. The other body helper is made inside our cells and can be changed into the first one with the help of vitamins.
The researchers wanted to see if the balance of these two body helpers, along with exposure to air pollution, could be linked to dementia.
The study took place in Stockholm, Sweden, and followed over 2,500 older adults for up to 12 years. During the study, 376 people developed dementia. The researchers collected data using interviews, blood tests, and questions about diet and exercise.
They found that people who developed dementia had slightly more exposure to PM2.5. These people also had higher levels of one body helper and lower levels of the other in their blood.
Even after taking into account factors like age, sex, smoking, and education, the results showed that a small rise in PM2.5 exposure was linked to a 70% higher risk of dementia. Half of this risk seemed to be related to the levels of the body helpers.
This suggests there may be a connection between air pollution, these substances in the body, and brain health. Scientists think dirty air might harm the brain through inflammation or other processes, but they’re not exactly sure how yet. More research is needed to fully understand what’s going on.
These findings remind us how important clean air is—not just for breathing, but also for thinking clearly and protecting our brains as we age. The study also points to the role of a healthy diet, since food affects the levels of the helpful substances in our bodies.
In the future, studies will look more closely at how air pollution and body chemistry work together to affect dementia risk. Meanwhile, we can take steps to support our brain health by eating well, staying active, and doing what we can to reduce exposure to polluted air.
If you care about dementia, please read studies about dietary strategies to ward off dementia, and how omega-3 fatty acids fuel your mind.
For more health information, please see recent studies about Choline deficiency linked to Alzheimer’s disease, and what to eat (and avoid) for dementia prevention.
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