There are many causes of the obesity epidemic – inactivity, genetics, and poor dietary choices are the most obvious culprits. Environmental factors such as a lack of pedestrian friendly areas or access to fresh food also contribute to the prevalence of obesity. It now appears that chronic exposure to air pollution may also have an impact on body mass according to a preliminary study recently published in the journal of the Federation of American Societies for Experimental Biology (FASEB).

It had previously been known that air pollution can serve as a risk factor for childhood obesity and that the impact of exposure to air pollution early in life can contribute to insulin resistance or weight gain into adulthood. This study presents the first data on the connection between air pollution and weight increases which are not related to diet. The researchers exposed rats to polluted air from Beijing and found that it resulted in added weight plus metabolic and cardiorespiratory dysfunction. Pregnant rats in the experimental group were considerably heavier at the end of the gestation period than their counterparts in the control group who were exposed to filtered air.

The baby rats who were exposed to the polluted air in the womb and after birth were also heavier at eight weeks old than the babies who were breathing filtered air. Additional problems were observed in the rats and their offspring who were exposed continuously to the unfiltered air including inflammation in the lungs, oxidative stress, high cholesterol, and inflammation in the epididymal area. The results may mean that weight gain resulting from metabolic dysfunction may begin in the lungs.

It is worth noting that this has only been shown in rats but the implications are major. The obesity epidemic is not only a scourge on the waistline, it’s also a major blight on the bottom line – it is estimated that obesity cost the US economy $147 billion in 2008. The United States is not the only country facing this problem – it’s a global health issue. This new evidence indicates that air quality is an important factor to achieving/maintaining a healthy weight.