Lactose intolerance causes difficulty digesting dairy products that contain lactose (milk sugar). It is particularly common amon
g people of African and Asian ancestry. In the United States (ignoring other groups and people who consider themselves to belong to more than one race), 82% of the population is White, 14% is Black, and 4% is Asian. Moreover, 15% of Whites, 70% of Blacks, and 90% of Asians are lactose intolerant.