“Fewer than 1 percent of people in the U.S. have a wheat allergy, and few than 1 percent have celiac disease, an autoimmune disorder that requires sufferers to refrain from gluten . . . Nonetheless, at least one in five Americans regularly chooses gluten-free foods, according to a 2015 poll. Sales of products with gluten-free labels rose to $23 billion worldwide in 2014 up from $11 billion in worldwide in 2010.” Relax, You don’t need to ‘Eat Clean’, Aaron Carroll, Nov. 4, 2017. New York Times Sunday Review Opinion.