Three out of every four people over age forty-five can no longer digest milk protein (termed lactose intolerance). True dairy allergy often occurs in infants, but is usually outgrown by the time they are two or three years old. Rashes, hives, vomiting, or diarrhea are the most likely symptoms. Casein, a protein in the milk, is what creates problems; it’s not the milk sugar (lactose).

When looking for milk substitutes, pay attention if you are allergic to gluten. Many rice milks contain gluten. Some products have this clearly labeled, while some don’t include the information or keep it hidden.

Casein can be difficult to avoid, particularly since many “dairy-free” products (whipped toppings, creamers, and so on) contain casein. It may be helpful to watch for the “kosher” symbol on foods, making sure it is not followed by a “D,” which indicates the presence of dairy.