Overall, about 75 percent of the world's population, including 25 percent of those in the U.S., lose their lactase enzymes after weaning.7 The recognition of this fact has resulted in an important change in terminology: Those who could not digest milk were once called "lactose intolerant" or "lactase deficient." They are now regarded as normal, while those adults who retain the enzymes allowing them to digest milk are called "lactase persistent."
There is no reason for people with lactose intolerance to push themselves to drink milk. Indeed, milk does not offer any nutrients that cannot be found in a healthier form in other foods. Surprisingly, milk-drinking does not even appear to prevent osteoporosis, its major selling point.