Q: What is lactose intolerance?

A: Lactose intolerance is an inability to completely digest the milk sugar lactose. Certain ethnic groups are genetically more susceptible to lactose intolerance, yet most of us will experience an increase in lactose intolerance as we age.

The reason for lactose intolerance is usually due to a decrease in the enzyme lactase, which is needed to digest the milk sugar into smaller units that can be absorbed through the GI tract. The enzyme is made in the small intestine where nutrient absorption occurs. It sits at the cell surface like a pair of scissors waiting for the milk sugar to pass by. When it does, the enzyme snips the milk sugar into two smaller sugar units allowing it to be easily absorbed. A deficiency of the enzyme results in some of the milk sugar remaining intact and passing into the large intestine where gut bacteria use it for their own energy source producing gas as a byproduct.

The increased sugar concentration in the large intestine causes a fluid imbalance resulting in diarrhea. That’s why a lactose-intolerant individual will experience lower abdominal discomfort after consuming milk or products made with milk.

Most people self-diagnose their lactose intolerance and sometimes overestimate their actual intolerance level for milk and milk products. Getting a stomachache after eating pizza with extra cheese and a super ice cream sundae does not necessarily mean you have lac