DURHAM, N.C., Feb. 22 (UPI) -- Air pollution can increase the risk for obesity and diabetes, according to a study with lab rats exposed to the highly polluted air of Beijing.
Researchers at Duke University found the air caused metabolic dysfunction in rats, leading to obesity and the precursors of diabetes when compared to rats that had not been exposed to the air.
The air in China's capital, and the rest of the country, has become an increasing focus of health concerns in recent years and the country called two red alerts in two weeks in 2015 because of especially bad air conditions.
Previous studies have shown air pollution causes oxidative stress and inflammation in the organs and circulatory system, as well as an increased risk of death.
"If translated and verified in humans, these findings will support the urgent need to reduce air pollution, given the growing burden of obesity in today's highly polluted world," Junfeng Zhang, a professor of global and environmental health at Duke University, said in a press release.
For the study, published in the FASEB Journal, researchers exposed rats to either samples of polluted air from Beijing or filtered air.
Nineteen days into the experiment, rats exposed to unfiltered air had 50 percent higher bad cholesterol levels, 46 percent higher triglycerides, and 97 percent higher total cholesterol, as well as a higher insulin resistance level.
While the rats ate the same amount of food throughout the study, the rats breathing unfiltered air also gained more weight eight weeks into the study, with female rats 10 percent heavier and male rats 18 percent heavier than their counterparts breathing clean air.
"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," Zhang said.