Gluten-free diet may increase exposure to arsenic, mercury

Feb. 13 (UPI) -- Researchers at the University of Illinois at Chicago has found that people who eat a gluten-free diet may be exposed to increased levels of arsenic and mercury.

Exposure to high levels of arsenic and mercury can lead to cardiovascular disease, cancer and neurological effects.

Even though only less than 1 percent of Americans have been diagnosed with celiac disease, a negative immune response to gluten found in wheat, rye and barley, gluten-free diets have become more and more popular.

Roughly one-quarter of Americans said they were following gluten-free diets in 2015, a 67 percent increase from 2013. Gluten-free products use rice flour instead of wheat, and rice contains toxic metals including arsenic and mercury from fertilizers, soil and water.

A team from UIC School of Public Health examined data from the National Health and Nutrition Examination Survey and found 73 of the total 7,471 study participants who claimed to follow a gluten-free diet.

The survey consisted of participants ranging in age from 6 to 80 years old and was taken between 2009 and 2014.

Researchers found twice the levels of arsenic in the urine and nearly 70 percent higher levels of mercury in the blood of the participants who reported following a gluten-free diet compared to those who did not.

"These results indicate that there could be unintended consequences of eating a gluten-free diet," Maria Argos, assistant professor of epidemiology in the UIC School of Public Health and co-author of the study, said in a press release. "But until we perform the studies to determine if there are corresponding health consequences that could be related to higher levels of exposure to arsenic and mercury by eating gluten-free, more research is needed before we can determine whether this diet poses a significant health risk."

Argos said the United States regulates the levels of arsenic in water but not rice flour, unlike in Europe where there are regulations for food-based arsenic exposure as well.

The study was published in Epidemiology.