The number of people in the UK with type 2 diabetes has trebled over the last two decades, rising from 700,000 in the 1990s to 2.8 million today, which costs the NHS around £14 billion a year.
The increased numbers have been linked to rising levels of obesity, but a new study from the US suggests that air pollution may be responsible for at least one in 10 cases in Britain.
It found that the number of people with diabetes rose as air pollution increased, even when particulates were below levels deemed safe by the World Health Organisation (WHO). “Air pollution is a major driver of illness and should not be ignored,” said Dr Ziyad Al-Aly, assistant professor of medicine at Washington University.
“In the UK, in 2016 there were about 14900 incident cases of diabetes attributable to air pollution and 31800 healthy life years lost.
“We did not look at the city level or London. However, it is very clear from our results that higher (pollution) is associated with higher risk.”
Type 2 diabetes occurs when an individual does not produce enough insulin, the hormone that allows cells to absorb glucose into the blood, or when the insulin that is produced does not work properly. As a result, blood sugars build up in the body and the cells do not receive the energy they need.
Over time type 2 diabetes can lead to damage to the blood vessels, nerves and organs and trigger kidney disease and blindness. It also increases the risk of a heart attack and stroke.
For the study, researchers looked at the health records of 1.7 million US veterans who were followed for an average of 8.5 years. Using Nasa satellite data and ground station readings to monitor air pollution they linked the readings to individuals to find the quality of air they had been breathing.
They also cross referenced air pollution in 194 countries with the Global Burden of Disease study to find out whether diabetes cases rose in more polluted areas.
Although previous studies have suggested that pollution may trigger diabetes by inflaming the airways and stopping insulin from processing blood sugar, the study is the first to see if it is actually happening at a population level and quantify the effect.
Researchers previously thought diabetes was linked to the obesity epidemic, but air pollution may also be playing a role
Overall, the researchers estimated that pollution contributed to 3.2 million new diabetes cases globally in 2016, which represents about 14 percent of all new cases.
When that exposure increases to 11.9 to 13.6 micrograms per cubic metere of air, about 24 percent of the group developed diabetes. In Britain the average level of air pollution is 12 micrograms per cubic metre of air, but often rises to 50 or 60 in inner cities like London.
Dr Emily Burns, Head of Research Communications at Diabetes UK, said: “Given the number of people living in heavily polluted areas, this suggests that even a small reduction in air pollution may have an impact on numbers of people developing Type 2 diabetes.
“And while taking steps to meet air quality standards will have a substantial impact on our collective health, there are still ways to reduce your risk of Type 2 diabetes today through a healthy diet and getting active.”
The findings, which are published in The Lancet Planetary Health, raise the possibility that reducing pollution may lead to a drop in diabetes.