Many of the gluten substitutes in use today just “cannot match the nutritional prowess of wheat,” Shelke contends. Wheat’s nutrients-particularly found in whole wheat flour-include B vitamins, iron, calcium, vitamin D, vitamin E, fiber, protein, and such minerals as magnesium, copper, and zinc. “People who are on gluten-free diets,” Shelke says, “especially children, are vulnerable to nutrient deficiencies.” The refined starches of gluten-free favorites potato and rice flour can also cause blood-sugar issues in consumers: the higher glycemic indices of these substitutes can produce greater spikes in blood sugar than certain wheat products do.
