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Is Pollution Making Us Fat?

Multiple studies reveal that the particles in the air you breathe could increase your risk of diabetes and obesity.

| 3 min read

Multiple studies reveal that the particles in the air you breathe could increase your risk of diabetes and obesity.

A slew of studies have pointed to the fact that pollution may not purely be an environmental issue — tiny airborne particles might also be contributing to a number of health issues related to weight, like obesity, heart disease, and diabetes. In fact, two people could eat the same foods and do the same amount of exercise, but depending on the atmosphere around their homes, one could put on more weight and develop a faulty metabolism.

Two of the key culprits are traffic fumes and cigarette smoke since the tiny particles disrupt the body’s ability to burn energy. While smog is most commonly associated with respiratory diseases, the pollution could contribute to a number of other serious diseases as well. “We are starting to understand that the uptake and circulation of air pollution in the body can affect more than just the lungs,” Hong Chen, a researcher at Public Health Ontario and the Institute of Clinical Evaluative Sciences in Canada, told BBC Future.

SEE ALSO: Obesity: Candy, Soda, Fast Food Aren’t to Blame, Study Finds

Chen examined medical records of 62,000 people in Ontario throughout a 14-year period. Troublingly, he found that the risk of diabetes increased by about 11 percent for every 10 micrograms of particles in a cubic meter of air. What’s even more troubling is that some highly-polluted Asian cities, like Beijing, reach at least 500 micrograms per cubic meter of air.

An older study looked at the effects of air pollution on laboratory mice. Since city-dwellers seem to be at a higher risk of heart disease compared to those who live in the countryside, Qinghua Sun at Ohio State University decided to determine whether the air had anything to do with it.

He split the mice into groups and raised them in the opposing city-countryside conditions: some breathed clean, filtered air, while others breathed in the kind of fumes that would be floating around in a busy city or next to a motorway. After just 10 weeks, the researchers could see significant changes. The mice who were exposed to the air pollution had greater volumes of body fat around the belly and internal organs, and the fat cells themselves were 20 percent larger.

Another unsettling observation was that the “city” mice were less sensitive to insulin, which is the hormone that signals cells to convert blood sugar into energy. As BBC Future reports, insulin resistance is one of the first steps toward diabetes.

Air pollution could also have striking effects on babies and young children, negatively impacting the generations to come with weight issues. Scientists have been particularly concerned that a mother’s exposure to certain pollutants could make a baby more prone to obesity by altering its metabolism.

Andrew Rundle, an associate professor of epidemiology at Columbia University, studied the effects of exposure to air pollution during pregnancy. During pregnancy, the mothers in the study wore small backpacks that measured air quality, and then the researchers monitored the children’s health at regular intervals over the next seven years. After controlling for factors like wealth and diet, the scientists found that children born in the most polluted areas were 2.3 times more likely to become obese than those living in clean neighborhoods.

Robert Brook, an associate professor of internal medicine at the University of Michigan, studied the effects of smog in Beijing over a two-year period, again finding a link with problems like insulin resistance.

“In North America and Europe the pollution levels have been trending in right direction – but we shouldn’t rest on our laurels,” he told BBC Future. “From the standpoint of improving health across the world, it should be one of our top 10 worries.”

It’s important to note that while these studies have all shown a significant link between air pollution and weight-related issues, they haven’t shown that one factor causes another.

Nonetheless, it’s certainly important to keep the issue on our radar. Even if making the effort to clean up the air doesn’t solve our problems with obesity and diabetes, the worst thing it can do is save our planet…

Read next: Eating Sweets Could Actually Help Control Eating Habits

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