Who would have thought that even water might lead to type 2 diabetes. It’s not exactly the water, but the low levels of arsenic found in the tap water used by 13 million people in the United States.

According to the US Environmental Protection Agency, the levels of inorganic arsenic should not be higher than 10 micrograms per liter, but the study conducted by Ana Navas-Acien, of the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland and colleagues found that levels in tap water are higher than this. And the situation is getting worse as people in other countries of the world are exposed to much higher levels of arsenic.

“In terms of magnitude, people in Taiwan and Bangladesh are exposed to at least 10 times higher levels compared to people in the U.S. We were interested in investigating if arsenic exposure at low and moderate levels could be related to diabetes,” Navas-Acien said.

For the study, the researchers analyzed 788 adults age 20 and older who had their urine tested for arsenic levels as part of a study conducted by the National Health and Nutrition Examination Survey in 2003-2004, a nationwide health study that for the first time collected and tested arsenic levels in urine.

The study found that participants with type 2 diabetes had a 26 percent higher level of total arsenic in their urine compared to those not having the disease. After adjusting risk factors for diabetes and seafood intake (seafood also contains nontoxic organic arsenic), researchers found participants in the top one-fifth of total urine arsenic levels (16.5 micrograms per liter) had 3.6 times the chances of having type 2 diabetes as those in the lowest one-fifth (3 micrograms per liter).

One possible explanation for this finding could be the fact that arsenic influences genetic factors that interfere with insulin sensitivity and other processes or that it contributes to oxygen-related cell damage, inflammation and cell death, which have also been related to diabetes, the authors concluded.

“Given widespread exposure to inorganic arsenic from drinking water worldwide, elucidating the contribution of arsenic to the diabetes epidemic is a public health research priority with potential implications for the prevention and control of diabetes.”

Arsenic is known to affect nearly all the organs in the body, causing ailments including lung, skin and kidney cancer, internal bleeding and heart damage, kidney and liver failure and birth defects.

John Hopkins researchers say the current study needs to be followed by others to show whether the arsenic exposure occurred first and then triggered the diabetes or the other way around, in which case, it is possible that diabetics were less able to filter out the poison.

Diabetes is the fifth leading cause of death in the United States. There are some 24 million Americans living with this disease, with 6.2 million not even knowing that they have it. To make things even worse, an additional 54 million Americans have pre-diabetes, placing them at high risk for developing type 2 diabetes.

The American Diabetes Association estimates there will be nearly 50.2 million people with diabetes by 2025, especially that obesity epidemic continues to spread. Adding environmental factors such as arsenic exposure to the equation, the number could be higher than this if things are not dealt properly.

The study findings were published in the August 20 issue of the Journal of the American Medical Association.