Air pollution is already known to be bad for our lungs and heart, but now scientists have found it may also hurt our metabolism.
A new study from the University of Zurich and Case Western Reserve University shows that breathing polluted air for a long time can damage how our bodies control blood sugar.
This could raise the risk of problems like insulin resistance and type 2 diabetes.
The researchers focused on tiny particles in the air called PM2.5. These particles are so small that we can breathe them deep into our lungs. They come from things like car exhaust, smoke, and factory pollution. To see how PM2.5 affects the body, the scientists ran an experiment on mice.
Some mice were exposed to clean, filtered air, while others breathed air filled with PM2.5 for six hours a day, five days a week, over 24 weeks. This setup was meant to copy what it’s like to live in a polluted city.
After this time, the mice breathing the polluted air showed signs of poor metabolism. They had trouble using insulin properly, which is a sign of insulin resistance.
One important part of the study looked at brown fat, a special type of body fat that burns energy and helps control blood sugar. In the mice exposed to air pollution, this brown fat didn’t work properly.
The researchers found that many important genes in brown fat—genes that help produce heat, break down fat, and protect cells from damage—were no longer working as they should. The brown fat also showed signs of damage and extra fat buildup.
The scientists then explored what was causing these changes in gene behavior. They discovered that pollution had changed the way genes are turned on or off in the brown fat cells.
These changes didn’t involve mutations in the genes themselves but instead involved something called epigenetics. This means that pollution changed how the genes were controlled.
Two enzymes, named HDAC9 and KDM2B, were found to be responsible. These enzymes affect the proteins (called histones) that DNA wraps around. In polluted mice, these enzymes reduced important chemical markers that help genes do their jobs.
When the researchers blocked these enzymes, the brown fat worked better. But when they made the enzymes more active, metabolism got worse.
This study shows that air pollution can lead to harmful changes in the body’s metabolism, not just by damaging the lungs but also by changing how genes work in brown fat. These changes may raise the risk of diabetes and other health issues.
The researchers hope this information can help find new ways to prevent or treat these problems.
If you care about diabetes, please read studies about How to choosing the right fruits for type 2 diabetes and findings of New higher dose diabetes drug promises better blood sugar control and weight loss.
If you care about diabetes, please read studies about The hidden connection between cancer and diabetes uncovered and findings of Scientists find the best way to help people with diabetes lose weight.
The study is published in JCI Insight.
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