Is Air Pollution Giving Us More Diabetes?

New research in Lancet Planetary Health finds that air pollution is adding to the global burden of diabetes. In fact, researchers estimate that it contributed to 3.2 million new cases of type 2 diabetes in 2016 alone. Published yesterday, the study suggest that cuts in air pollution might help reverse global trends toward a crushing epidemic of type 2 diabetes.

Even at levels below EPA standards for clean air, pollution can add to the risk of diabetes, said Benjamin Bowe and colleagues in their paper. The risk comes from fine particles of dust, dirt, smoke, soot, and droplets suspended in the air. They have many sources, both natural and human. But industrial activity and fossil fuels are driving global levels up.

Strengths and Limitations of the Research

Establishing causality for a risk factor like this is no small task. Bowe et al conducted a longitudinal cohort study of U.S. veterans to quantify the relationship between this pollution and the risk for developing diabetes. They tested against both positive and negative outcome controls. And they used data and methods from the landmark Global Burden of Disease project to estimate the global burden of diabetes attributable to fine particle pollution.

The controls, especially the negative controls, are a strength of the study. But the researchers were not able to adjust for individual parameters like physical activity. So confounding is always a possibility.

Pollution Already Linked to Both Diabetes and Obesity

Despite the inevitable limitations, it’s worth noting that considerable evidence explains the mechanisms linking particulate pollution to both diabetes and obesity. Animal research helps to explain it. And this research fills in some important gaps by quantifying the risk in a rigorous way.

In a companion commentary, Gary O’Donovan and Carlos Cadena-Gaitán offer a hopeful perspective. We can certainly do more research to study the interactions between diabetes, obesity, physical activity, and air pollution. But already, we know plenty to take action. Policies can simultaneously serve to reduce air pollution and promote physical activity. Promoting active transportation schemes and discouraging fossil fuels for transport is just one example.

It’s definitely time to move on this issue, they say, and we agree.

Click here for the study, here for the commentary, here for the press release, and here for more from CNN.

Paris Hidden Behind Its Mistakes, photograph © Clément Costa / flickr

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June 30, 2018