Heart Disease 8. A few children and many people after childhood do not produce sufficient lactase, which impairs the body's ability to digest milk. These individuals are lactose intolerant and suffer from symptoms including cramps, gas, and diarrhea . If symptoms result from milk but not cheese, then the person has lactose intolerance. If symptoms occur with both milk and cheese, the person may be allergic to dairy.
Lactase is produced by the body.
Dairy products have varying levels of lactose, which affects how much lactase is required for proper digestion. Only one-third of all people retain the ability to digest lactose into adulthood. Most individuals of Asian, African, and Native American descent are lactose intolerant. In addition, half of Hispanics and about 20 percent of Caucasians do not produce lactase as adults. Lactose-reduced milk is available and can be used in the same quantities as regular milk.