GONE FISHING: Great Lakes fishermen were studied to understand the link between pesticides in fish and diabetes
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Eat right and exercise, conventional wisdom has it, if you want to avoid joining the diabetes epidemic.

But a new study adds some muscle to a growing body of research suggesting those steps, though beneficial, might not be enough for people exposed to chemicals in the environment.

The scientists linked diabetes and people’s body burdens of DDE, a chemical produced as the body breaks down the pesticide DDT, banned in the United States more than 35 years ago.

“Even though we haven’t used DDT in decades, its metabolites are still detected in almost everyone in the country,” said lead researcher Mary Turyk, an epidemiologist at the University of Illinois-Chicago’s School of Public Health.

Since the early 1990s, researchers have monitored a group of Great Lakes charter boat captains, recreational fishermen and others to learn about the health effects of eating fish tainted with persistent organic pollutants – chemicals that remain in the environment for decades and grow more concentrated as they move up food chains.

For the new study, blood samples from the Great Lakes group showed “consistent, dose-related associations of DDE” with diabetes, the researchers wrote in the July issue of Environmental Health Perspectives.

Among 471 adults, including 36 with diabetes, there was no link to the disease based on the amount of fish consumed or exposure to other pollutants. But the higher the concentration of DDE in the blood, the more likely they were to develop diabetes.

The study is among the strongest voices in a chorus of research supporting the link between environmental chemicals and diabetes, according to David O. Carpenter, director of the Institute for Health and the Environment at the University of Albany in New York. He was not involved in the study.

“Most people have not thought of diabetes as a disease related to environmental exposure,” he said, “and these studies show that it is. The science has been growing very, very rapidly, and to my mind, it’s one of the most exciting developments in the study of diabetes.”

Diabetics cannot produce or use enough insulin, a hormone that lets glucose – the body’s fuel – enter cells. More than 23 million Americans, or eight percent of the population, are diabetic, and that group swelled by 13.5 percent from 2005 to 2007, according to the American Diabetes Assn.

For the most common type of diabetes, Type 2, obesity and lack of exercise play a key role. The bulk of studies searching for a cause have focused on lifestyle factors, while research on environmental influences hasn’t been prominent in journals devoted to the disease, said Henry Kahn, an epidemiologist with the Centers for Disease Control and Prevention’s Division of Diabetes Translation.

“But maybe it should be. It would be foolish to overlook pollution as a factor,” he said, adding that he and colleagues have lately taken a greater interest in the role of pollutants. “We recognize it’s possibly a very important thing,” he said. “We agree it’s on the list of things worth studying.”

Oliver Jones, a biochemist at the University of Cambridge, wrote in the journal Lancet last year that “if there is indeed a link” between contaminants and diabetes, “the health implications could be tremendous. There has been almost no consideration for the possible influence of environmental factors such as pollution."