Over the past few years, you may have noticed that a lot of (occasionally smug) people have jumped on the gluten-free bandwagon. It's a major trend in food consumption in America: Whereas only 1% of the U.S. population has celiac disease, around a quarter of Americans identified as gluten-intolerant in 2015, a jump of 65% from just two years earlier.

But those bandwagon jumpers may have gotten more than they bargained for: an extra dose of toxic metals.

Arsenic and mercury may be more prevalent in the diets of those who stick to gluten-free meals, according to a new University of Illinois study published in the journal Epidemiology. Researchers combed through the almost 8,000 people in the National Health and Nutrition Examination Survey, and focused on the 73 people who claimed to stick with a diet totally free of gluten. The researchers checked the study participants' blood and urine test results between 2009 and 2014, and found that the arsenic levels were about twice that of non gluten-free eaters, along with mercury levels that were 70% higher.

Why the high levels of toxins? The researchers suggest that processed, gluten-free products usually replace wheat with rice, which has been found to suck up higher proportions of toxic metals from fertilizer, soil, or water.

“We regulate levels of arsenic in water, but if rice flour consumption increases the risk for exposure to arsenic, it would make sense to regulate the metal in foods as well," said study author Maria Argos, Ph.D., an assistant professor of epidemiology in the UIC School of Public Health.

In the meantime, if you are truly gluten intolerant—and you should check with your doctor; don’t just decide you are because your tummy gets upset sometimes—eat products that are labeled organic, which are grown without heavy pesticides or herbicides and therefore (in theory) lessen your risk of ingesting toxic metals. Try also to eat more naturally gluten-free food like fruits, veggies, lean meats, cheese, yogurt, and nuts and seeds. You know: Real food, and not manufactured crap from a box. It's what you should be eating anyway.