Essential micronutrient and toxic trace element concentrations in gluten containing and gluten-free foods.

For individuals following a gluten-free (GF) diet, rice is commonly the major grain. People following a GF diet have a higher arsenic burden than the general population. We conducted a multielemental market basket study of GF and gluten containing ingredients and prepared foods (Mn, Fe, Ni, Cu, Zn, Cr, Co, Se, Cd, Sb, Pb, total As, As species, total Hg and methylmercury). Foods containing rice were significantly higher in As, Hg and Pb and lower in Se, Fe, Cu and Zn. Wheat-based foods were higher in Cd. Mercury concentrations were low (<3.5 ng/g); speciation was predominantly methylmercury. Arsenic and mercury in rice were correlated. GF foods contained significantly more As and Hg. Eating a wide variety of GF grains may reduce contaminant exposure and increase micronutrient status compared to a rice-based GF diet.