Even at apparently safe levels, outdoor air pollution has been linked to an increased risk of diabetes globally, said a new study published in The Lancet Planetary Health.
Conversely, the findings raise the possibility that reducing pollution might lead to a drop in diabetes cases in heavily-polluted countries such as China and India. The study from Washington University School of Medicine in St. Louis and the Veterans Affairs (VA) St. Louis Health Care System estimated that pollution contributed to 3.2 million new diabetes cases globally in 2016.
This total represents about 14 percent of all new diabetes cases globally in 2016. The study also estimated that 8.2 million years of healthy life were lost in 2016 due to pollution-linked diabetes. This total represents 14 percent of all years of healthy life lost due to diabetes from any cause.
The study blamed 150,000 new cases per year in the USA on air pollution along with a corresponding 350,000 years of healthy life lost. Pollution worsens diabetes by reducing insulin production and triggering inflammation. These actions prevent the body from converting blood glucose into energy the body needs to stay healthy.
Diabetes is spreading rapidly worldwide, driven by high-sugar diets, obesity, and sedentary lifestyles. It's a curse of more than 420 million people worldwide. Outdoor air pollution must now be added to these causes.
"Our research shows a significant link between air pollution and diabetes globally," said Ziyad Al-Aly, MD, the study's senior author and an assistant professor of medicine at Washington University. He said his team found an increased risk of diabetes even at low levels of air pollution considered safe by the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA).
Researchers looked at particulate matter and airborne microscopic pieces of dust, dirt, smoke, and soot when evaluating the effect of outdoor air pollution on diabetes. These microscopic particles, especially PM2.5 (the deadliest), enter the lungs and bloodstream carried by air pollutants such as motor vehicle exhaust.
The microscopic PM2.5 can lead to a 36 percent increase in lung cancer per 10 μg/m3 when it penetrates deeply into the lungs. Particulate matter can also trigger heart disease, stroke, cancer and kidney disease.
Researchers also found that the overall risk of pollution-related diabetes is skewed more toward lower-income countries such as China and India. For instance, poverty-stricken countries face a higher diabetes-pollution risk, while richer countries experience a lower risk. The U.S. experiences a moderate risk of pollution-related diabetes.
