Test on rats shows air pollution increases risk of obesity

A new study shows laboratory rats that breathed Beijing's highly polluted air gained weight and experienced cardiorespiratory and metabolic dysfunctions.

The Duke University-led study has published the result in the March issue of the Journal of the Federation of American Societies for Experimental Biology (FASEB).

Zhang Junfeng, a professor of global and environmental health at Duke and a senior author of the paper, said the research aims to understand the factors leading to obesity besides diet and sports, Caixin.com reports.

In the study, pregnant rats and their offspring were placed in two chambers – one exposed to filtered air that removed most of the air pollution particles and the other to Beijing's highly polluted air.

The research showed that the lungs and livers of pregnant rats exposed to the polluted air were heavier and showed increased tissue inflammation after only 19 days. Similar results were shown in the rat offspring, which were kept in the same chambers as their mothers.

The levels of LDL cholesterol, triglycerides, total cholesterol, and insulin resistance, a precursor of Type 2 diabetes, were higher than their clean air-breathing counterparts.

Zhang said the research provides clear evidence that chronic exposure to air pollution increases the risk for developing obesity.

Data from the research also show that the actual consumption of food by the pollution-exposed rats was larger, perhaps due to the requirement for more energy to breath with inflamed livers and lungs, Zhang added.

The study is consistent with a report about the China Obesity Index, which showed the obesity rate in northern China, suffering more from air pollution, was higher than that in the southern region.

Zhang said it's highly possible that air pollution contributes to obesity, but more prudent research is needed as dietary and sports are still dominant factors.