New study links BPA exposure to increased risk of type 2 diabetes

High levels of exposure to the chemical bisphenol-A, or BPA as it is commonly known, may increase a person's risk of developing type 2 diabetes, according to a new study.

The finding is the latest in a string of recent reports to suggest that BPA may contribute to the development of metabolic disorders. While there is still no conclusive proof indicating that the chemical directly causes diabetes, science is increasingly moving toward this conclusion.

For the present study, a team of researchers from West Virginia University analyzed urine samples collected between 2003 and 2008 as part of the National Health and Nutrition Examination Survey. The results, which were published in the Journal of Clinical Endocrinology and Metabolism, showed that higher levels of BPA were associated with an increased risk of developing type 2 diabetes.
Furthermore, the researchers said that this association persisted regardless of age, gender, race or body mass index, other factors that may potentially contribute to a person's overall risk of developing type 2 diabetes.
"Urinary BPA levels are found to be associated with diabetes mellitus independent of traditional diabetes risk factors," the team wrote in their report. "Future prospective studies are needed to confirm or disprove this finding."

Still, the findings cannot prove that BPA exposure caused individuals to develop type 2 diabetes. Since only one sample was tested, it would be impossible to say that high levels of the chemical were present in participants' systems before they developed the metabolic condition. This is why the team recommended further investigation.

The findings could have important implications for society. BPA is used in a range of food products that may allow the chemical to enter a person's system. It is a common component of many plastics and is often used to line aluminum cans. Studies have shown that more than 90 percent of Americans may have some level of BPA in their system.

While the exact cause of the correlation between BPA and type 2 diabetes is not precisely known, scientists believe it has to do with the fact that the molecular structure of the chemical resembles that of a sex hormone, namely estradiol. Because of this, BPA is known as an endocrine disruptor.

There has been little action to restrict the use of BPA in the U.S. The FDA has issued a warning indicating that high levels of exposure to the chemical during pregnancy may cause birth defects, but has not moved to place stricter regulations on it. However, the Canadian government has classified BPA as a toxin, making it subject to more control.

Despite the fact that researchers have yet to be able to show a direct link between BPA exposure and type 2 diabetes, findings are increasingly associating the two. Further clarifying the picture and taking appropriate steps to regulate the chemical could play an important role in slowing the increase in type 2 diabetes rates currently being seen in the general public.