What is lactose intolerance?

Lactose is a sugar present in mammalian milk. For its digestion, it must be broken down into glucose and galactose, a process mediated by the necessary action of an enzyme called lactase. This reaction takes place in the intestine, specifically in the villi of the small intestine, which are responsible for producing lactase.

The problem comes when lactase levels are low, lactose cannot be broken down and it continues on its way to the large intestine, thus triggering all the symptoms of lactose intolerance (stomach cramps, bloating, diarrhea and nausea).

The origin of lactose intolerance can be:

  • Genetic. This intolerance is caused by an alteration in a gene called MCM6 that controls the lactose gene (LCT). In these cases, lactase loss occurs throughout life.
  • Others. Lower lactase production due to different reasons: in this case it is possible that lactose intolerance is temporary, that is, our body can produce less lactase as a result of problems that affect the small intestine, such as celiac disease.


What is your relationship with Celiac Disease?

When people with Celiac Disease eat foods with gluten, their immune system reacts by causing damage to the intestinal villi. Damaged villi could lead to the amount of lactase that the body will produce can be much lower and will not help to break the lactose in two.

For this reason, many people at the time of being diagnosed with celiac disease, have low levels of lactase and can also be diagnosed with lactose intolerance. Sometimes, with a gluten-free diet and the consequent improvement of the villi, this intolerance can be corrected or be very mild. But sometimes that doesn’t happen, so someone with celiac disease and lactose intolerance, in addition to following a strict gluten-free diet, will also have to eliminate lactose from their diet.