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Is breathing making some of us fat?

Kathleen Blanchard's picture
air pollution linked to obesity

It may sound extreme, but there is new evidence that breathing might be contributing to the obesity epidemic. You might be asking how it's possible. Weight gain and obesity could be fueled by air pollution.


Researchers publishing in the Federation of American Societies for Experimental Biology (FASEB) linked obesity in rats to the air the rodents were breathing.

According to the new study, breathing bad air could cause us to get fat by promoting inflammation that in turn triggers a cascade of metabolic events that can cause weight gain. The mice gained weight after just 19 days of being exposed to air pollution.

What happened

Image Wikimedia Commons

For the study Junfeng "Jim" Zhang, a professor of global and environmental health at Duke University and a senior author of the paper and his team studied two groups of rats.

One group of pregnant rats was exposed to air in Beijing and the other group was placed in a filtered air chamber. It's not surprising that after 19 days the rats breathing in air pollution showed signs of inflammation. They also weighed more than the control group of rodents and they had insulin resistance that is a precursor to type 2 diabetes.

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Rats exposed to air pollution also had higher cholesterol and triglyceride levels, both of which are precursors to metabolic syndrome.

After 8 weeks of exposure things got worse. The rats showed even worsening inflammation, leading the scientists to conclude air pollution promotes a continuous state of inflammation that eventually leads to metabolic changes that made the rats fat.

Zhang said in a media release: "Since chronic inflammation is recognized as a factor contributing to obesity and since metabolic diseases such as diabetes and obesity are closely related, our findings provide clear evidence that chronic exposure to air pollution increases the risk for developing obesity."

And in fact, many experts believe the secret to weight loss is controlling inflammation. One simple way to fight inflammation and avoid weight gain is by adding nuts to your diet.

See: Link between inflammation and obesity becomes clearer

The next step is to verify the findings in humans. Air pollution may end up as an addition to the growing list of causes of obesity that is now considered an epidemic that has surpassed smoking as the number one preventable disease.

Related: High altitudes linked to lower obesity rates