Pollutants may cause complications of obesity, study finds

Exposure to a certain type of man-made pollutant has been linked to the development of certain metabolic complications of obesity in humans by a pioneering new study.

Obesity can cause insulin resistance and type 2 diabetes but some obese people, categorised as being “metabolically healthy but obese“, appear to be resistant to such complications.

In attempting to understand why this is the case, the pioneering study, published this week in The Journal of Clinical Endocrinology & Metabolism, investigated the role of persistent organic pollutants (POPs).

POPs are manufactured chemicals used in agricultural, industrial and manufacturing processes. Though they are strictly regulated due to their impacts on health, POPs are extremely resistant and can still be found all over the world.

“Exposure to POPs comes primarily from the environment and the consumption of food such as fatty fish, meat and milk products,” says Jérôme Ruzzin, who worked on the study.

“As their name suggests, they are also persistent so the body cannot easily eliminate them. POPs can therefore have significant impacts on human health, and have been shown to affect reproduction, promote cancer, and be involved in the development of metabolic diseases.”

Recent research has found that POPs can accelerate the development of insulin resistence and obesity in mice. Therefore, the study sought to investigate whether metabolically healthy but obese people have lower levels of POPs in their system than those with complications. 

The team studied 76 obese women, finding that out of 18 detectable POPs, the women with cardiometabolic complications had higher concentrations of 12. 

“Remarkably, close to 70% of the detectable POPs were significantly higher in individuals with cardiometabolic complications compared to metabolically healthy but obese subjects,” explains Marie-Soleil Gauthier, a co-first author of the study.

 “Our study confirms that the two groups have distinct POP profiles, and that metabolically healthy but obese individuals have significantly lower circulating levels of various classes of POPs than patients with complications.” 

The research team stress that their study does not confirm a causal link, saying that further research is required.

“A better understanding of the role of POPs could lead to new directions for the prevention, diagnosis, and treatment of cardiometabolic risk associated with obesity,” Gauthier adds.

Further reading:

European air pollution limits still not adequate to reduce health risks

‘Alarming’ rise of cancer in developing world expected

UK obesity ‘worst case scenario’ might be underestimating problem

Number of overweight people in developing countries tripled since 1980

New European clean air plan seeks to mitigate cost of pollution