Lactose intolerance means you have trouble digesting milk and milk products. The condition is most common among Asians, American Indians, Mexican Americans, and blacks. It is also a more common problem as people get older. You can make changes in your diet that will help you better digest milk and milk products or allow you to get enough calcium from other sources. You have trouble digesting milk because your body does not produce enough lactase.
Lactase is the enzyme that breaks down the natural sugar found in milk.
This milk sugar is called lactose. The severity of the intolerance varies from one person to another. Many people with this problem are able to drink small amounts of milk, especially if they eat other foods with it. Others cannot drink any milk without having symptoms. The body naturally starts producing less lactase around age 6.