NEW YORK (Reuters Health) - People with higher levels of pesticides and other pollutants in their blood may be more likely to get type 2 diabetes, suggests a new study of elderly Swedes.
The findings add to a growing body of evidence that these chemicals might drive changes in the body that lead to diabetes, researchers say, although they don’t prove that one causes the other.
Taken together, the data suggest that there is more to the blood sugar disease than eating too much and not getting enough exercise, said Dr. David Carpenter, head of the Institute for Health and the Environment at the University at Albany in New York.
The pollutants, including pesticides and poly-chlorinated biphenyls, or PCBs, are largely found in meat and fatty fish. Some of them, including PCBs -- once used in paint, plastics, and for electrical equipment manufacturing -- are heavily regulated and no longer used in many countries.
However, “the exposure to these chemicals in the general population still occurs because they have widely contaminated our food chain,” study researcher Dr. Duk-Hee Lee, of Kyungpook National University in Daegu, South Korea, told Reuters Health in an email.
In the current study, Lee and colleagues sought to follow up on previous findings that had linked these chemicals with type 2 diabetes.
They recruited a group of 725 diabetes-free elderly adults in Sweden and took blood samples to measure their levels of the pollutants. Then, the researchers followed them for the next five years.
Thirty-six of the study participants were diagnosed with type 2 diabetes over that time. When Lee’s team accounted for other diabetes risks such as weight, exercise, and smoking, people who had high levels of PCBs were up to nine times more likely to get diabetes than those with very low pollutant levels in their blood.
The link was smaller for some pesticides, while others weren’t linked to diabetes at all, according to the findings, which are published in the journal Diabetes Care.
The authors note that the number of new diabetes cases was low, and the findings can’t prove that PCBs or other pollutants cause diabetes.
But research suggesting that’s the case is piling up, said Carpenter, who was not involved in the new study.
More than eight percent of the U.S. population has diabetes, according to the National Institutes of Health -- most of them type 2 diabetes.
Many studies have linked type 2 diabetes to overweight, lack of exercise and high blood pressure. In the new study, a big waistline was also a diabetes risk factor.
The authors speculate that long-term exposure to environmental pollutants could affect cells in the pancreas that secrete insulin, a hormone that regulates blood sugar.
It would make sense that heavier people are more at risk of diabetes, Carpenter added, because they’re also probably eating more fatty meat and fish high in these chemicals -- and they have more fat themselves where these chemicals are stored.
While researchers try to clear up just which pollutants may be linked to diabetes and how, strategies for preventing diabetes don’t change much, Carpenter said.
“I think the message isn’t really so different as it was when we thought diabetes was only a lifestyle disease,” he said. “It is important to reduce your consumption of animal fat,” and to be aware of how much fatty fish you’re eating.
Lee added that eating more vegetables and other plant-based foods, as well as exercising, can help the body get rid of these pollutants.
SOURCE: bit.ly/k9xRuK Diabetes Care, online June 23, 2011.