According to a new scientific study, air pollution can increase rates of obesity and diabetes.
Scientists used lab rats and exposed them to the highly polluted air of the Chinese capital Beijing. Air quality in the city is famously bad, and it now looks as though residents might be putting their health at risk, writes Stephen Feller for UPI.
Study shows air pollution negatively impacts health of rats
A team of researchers at Duke University found that the rats suffered metabolic dysfunction after being exposed to the air. They later suffered increased rates of obesity and scientists discovered the precursor of diabetes when compared to rats that had been exposed to normal air.
In recent years concerns have been growing over the air quality in Beijing and other Chinese cities. Authorities called two red alerts in 2015 when air conditions became particularly bad.
Previous research has shown that air pollution is also responsible for oxidative stress and inflammation of the organs and circulatory system. It also raises the risk of death.
Scientists to research potential impact on humans
“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.
The results of the study were published in the FASEB Journal, and researchers made the rats live in polluted air or filtered air. The team found that after 19 days, those who had been exposed to polluted air had 50% higher bad cholesterol levels, 46% higher triglycerides and 97% higher total cholesterol.
Researchers also found that they had a higher insulin resistance level. Although both groups of rats were given the same amount of food, those breathing polluted air had gained more weight after 8 weeks.
Male rats were 18% heavier and female rats 10% heavier compared to their counterparts.
Worrying results increase clamor over public health issues
“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.
It appears that long-term exposure is a factor as negative effects were worse after eight weeks than after three. That may mean that long-term exposure is necessary in order for metabolic and inflammatory changes to take place and increase body weight.
Expats living in China have complained that their waistlines are bulging, and rates of obesity among Chinese nationals are on the rise. In 2014 the Lancet conducted a study which found that 28% of Chinese adult males and 27% of females are overweight or obese.
Around 30 years ago that figure was almost zero. As it stands China has more fat people than any other country in the world apart from the United States.
Study author Junfeng Zhang said that many people are eating too much and not getting enough exercise. But pollution is also a serious factor in increasing obesity rates.
“Think about how many days children [in Beijing] are advised not to go outside and exercise” because of pollution, he said. “That contributes to weight gain, and then there’s this evidence that you inhale these things and it gets your body messed up, with the fat metabolism and sugar metabolism. That will slow things down, and energy will accumulate in the body.”