Q. I have read that people on a gluten-free diet have more arsenic in their urine and mercury in their blood. Can you speak about this?
A. Rice absorbs and concentrates arsenic and mercury in soil. People with celiac disease tend to eat more rice than those who also eat gluten-containing grains, and, thus, are at risk for increased heavy metal exposure. The levels depend on the soil where the rice is grown. In the US, rice from California has lower levels of arsenic than further east where rice is grown in former cotton fields which were heavily fertilized. White rice has lower levels of heavy metals than brown rice and some companies publish results from testing their rice.