It has been previously thought that obesity was the major contributor to the development of type 2 diabetes, a disease in which the body does not produce enough insulin.

New findings show that eating fish polluted by manmade toxic chemicals and industrial effluents in sea and soil could also increase diabetes risk.
Especially dangerous have been found to be high levels of pesticide DDT and industrial coolants called PCBs.

DDT is the first modern pesticide used mainly to control mosquito-borne malaria. It was banned in the United States back in 1972 due to its adverse effect on environment and health, many developing nations still use it for the same purpose.

Polychlorinated biphenyls (PCBs) are a class of manufactured chemicals that tend to last for many years, that do not break down easily and that are difficult to destroy.

Oily fish, such as salmon, is recommended by dieticians as being particularly beneficial for health but they often contain particularly high levels of PCBs. Despite being long-banned, DDT and PCBs persist in our soil and seas and enter our bodies through the food we eat.

The scientists have shown an existing link between these chemicals and insulin resistance and that obese people with these chemicals in their blood were more likely to develop diabetes than thin people with the same amount of chemicals.