Newly released study... https://www.ncbi.nlm.nih.gov/pubmed/28223206 "Conclusion: In an analysis of data collected from NHANES, persons on a GFD have significantly higher urine levels of total arsenic and blood levels of mercury, lead, and cadmium than persons not avoiding gluten. Studies are needed to determine the long-term effects of accumulation of these elements in persons on a GFD." Another study released back in 2015 showed elevated Mercury levels in people eating a GFD. https://www.ncbi.nlm.nih.gov/pubmed/25802516 "Conclusion: Data demonstrate a fourfold increase of mercury blood levels in celiac patients following a gluten-free diet. Further studies are needed to clarify its role in celiac mechanism. Doesn't seem too surprising to me knowing that many gluten-free bread products, snacks, and sweets contain rice flour, rice sweeteners, etc. Rice is known to contain higher levels of heavy metals. I wonder though if people who eat a GFD eat more fish though than other people as rice and fish were the 2 items mentioned in the new study?