Rainbow Pollution

Persistent Organic Pollution, Obesity, and Insulin Resistance

A new study in PLOS ONE adds to the evidence that the endocrine disrupting properties of persistent organic pollution can be a significant factor in the dual epidemic of obesity and diabetes. Jung-Wei Chang and colleagues examined the relationship between abdominal obesity, insulin resistance, and exposure to dioxin. They found a five-fold higher risk of elevated insulin resistance in people with abdominal obesity and dioxin exposure.

Dioxins are perhaps the prototype of a persistent organic pollutant. It’s released into the environment by a wide range of industrial processes, motor vehicles, and smoke. Dioxins were responsible for much of the toxicity of Agent Orange and the health harms suffered by people exposed to it during the Vietnam War.

These persistent pollutants may provide some insight into the complicated relationship between cities and obesity. In the U.S., obesity rates are lower in urban areas compared to suburban and rural areas. The greater walkability of cities offers a potential explanation. But in China, for example, the situation is precisely the opposite. Obesity and diabetes are concentrated in the the densely populated and polluted cities of China.

As the relationship between persistent organic pollution, obesity, and diabetes becomes increasingly clear, the real question becomes what can be done about it? The Endocrine Society calls for more research and action to reduce exposure to endocrine disrupting chemicals and prevent them from being introduced into the environment.

And we need to go further. We need to redouble our efforts to find better treatment options for reversing the damage done by the resulting epidemic of obesity and diabetes. Some of the zeal that goes into painting sugar as “toxic” should be directed toward real toxins in persistent organic pollution.

Click here for the study in PLOS ONE, here for the position statement of the Endocrine Society, and here for more on the complicated relationships between cities and obesity.

Rainbow Pollution, photograph © gambier20 / flickr

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January 20, 2016