Back in July, one of my blog posts focused on an article in the British Medical Journal which highlighted the problem of drug residues turning up in municipal water supplies. A new study just published in the Journal of the American Medical Association suggests that other dangers may lurk in drinking water in the form of arsenic. The study looked at the relationship between urine arsenic levels and risk of diabetes in 788 adults. Individuals with the highest levels of arsenic in their urine were found to be more than 3½ times more likely to develop diabetes compared to those with the lowest levels.
Epidemiological studies of this nature cannot prove that arsenic is causing diabetes ” all they can do is show an association between these two things. However, the results of strengthened by the fact that the researchers accounted for major risk factors for diabetes. This makes it more likely that the relationship between arsenic levels and diabetes is a real one.
Also, it is believed that there are several mechanisms through which arsenic might actually cause diabetes. For examples, cells exposed to arsenic are less able to take up sugar. And arsenic may also contribute free radical damage and inflammation in the body, both of which might increase diabetes risk.
A major source of arsenic is drinking water, which led the authors of this study to conclude that their finding: supports the hypothesis that low levels of exposure to inorganic arsenic in drinking water, a widespread exposure worldwide, may play a role in diabetes prevalence. They suggest further study in an effort to assess whether the arsenic in drinking water is causing diabetes or not.
However, the state of the evidence as it stands looks suspicious. And it’s another reason for believing that municipal drinking water supplies are not always as clean, pure and safe as some would have us believe them to be. In my blog in July I discuss some approaches (including the filtering of water) that might help to reduce exposure to hazardous substances. In this blog, I provided a link to the Freshwater Filter company in the UK. I phoned this company today to ask specifically about arsenic. I was told that their Freshwater 1000 and 2000 systems when fitted with either ‘Pearl’ or ‘Emerald’ cartridges are effective for clearing arsenic. For more details, contact the company.
Navas-Acien A, et al. Arsenic Exposure and Prevalence of Type 2 Diabetes in US Adults. JAMA. 2008;300(7):814-822.