Aug. 6, 2014 -- New U.S. labeling regulations for products that claim to be gluten free are a "major milestone," according to an expert.
Under the Food and Drug Administration rules that take effect Tuesday, packaged food labeled as being gluten free cannot contain more than 20 parts per million of gluten, the Los Angeles Times reported.
The use of the gluten-free label is voluntary, and products that contain gluten are not required to declare that on the package.
Gluten is a protein found in wheat, barley and rye. Consuming just a tiny bit of gluten can cause illness in people with an autoimmune disorder called celiac disease.
"The gluten-free diet for someone with celiac disease is like insulin for diabetics," Dr. Alessio Fasano, director of the Center for Celiac Research at Massachusetts General Hospital, told the Times.