Lactose intolerance

What is it?

Lactose intolerance is a pathology frequently encountered today. It occurs when the activity of lactase in the intestine is reduced or absent, with consequent failure to digest lactose.
Lactose intolerance and celiac disease are the most common food intolerances. In fact more and more peole , to the point that more and more people purchase gluten or lactose-free products on a daily basis.


What enzyme is responsible for lactose intolerance?
Lactose intolerance is usually the result of your body not producing enough lactase, an enzyme  normally produced in your small intestine that’s used to digest lactose.
Lactase increases as the ingestion of milk and derivatives increases.
In fact, the greatest production of lactase occurs in the newborns.
If your body does not produce enough lactase, lactose is not digested and absorbed in the small intestine in the usual way. Instead, it continues to travel along the digestive tract to the large intestine, where bacteria partially break it down into acids and gases, causing  cramps, abdominal pain, swollen abdomen, constipation and diarrhea.


The causes of lactose intolerance can be different:

Primary lactose intolerance (or congenital lactose intolerance) is a very rare genetic condition. In this case, the lactase enzyme loses its physiological function and the patient is genetically predisposed to develop lactose intolerance.

Secondary intolerance if it is caused by non-genetic factors such as:

  • GadstroIntestinal disorders;
  • Crohn’s disease;
  • Ulcerative colitis;
  • Celiac disease;
  • Intestinal infections;
  • Intestinal dysbiosis;
  • Too high intake of milk and dairy products.


The signs and symptoms of lactose intolerance usually begin from 30 minutes to two hours after eating or drinking foods that contain lactose. Common signs and symptoms include:

  • Nausea;
  • Meteorism;
  • Flatulence;
  • Bloating and tight stomach
  • Diarrhea;
  • Constipation;
  • Alternating constipation and diarrhea.

The severity of the symptoms will depend on how much lactose you have ingested and how much lactase your body makes.


A diagnosis of lactose intolerance can usually be made by a gastroenterologist or by a family doctor with the support of the one of these lab test:

  • Genetic test, to identify the variant of the gene encoding the lactase enzyme. The patient may have an variant predisposing to a sensitivity to lactose or a variant subject to a mutation over time.
  • The most common noninvasive method of diagnosing lactose intolerance is a breath hydrogen test. This test measures the amount of hydrogen gas in your breath before and after you drink a liquid containing lactose.


The mainstay of treatment for lactose intolerance is lifestyle and diet modification that includes decreasing the consumption of dairy products or switcing to lactose-free or reduced lactose dairy products and the use of lactase enzyme tablets or drops.
However, in the most severe cases it is also advisable to follow detoxifying diet based on the following guidelines:

  • Use of whole grains with greater soothing action for the intestinal mucosa;
  • Avoid red meat and cured meats, rich in saturated fats;
  • Drink still water with a less inflammatory and corrosive action on the intestinal mucosa;
  • Prefer less aggressive cooking methods such as steaming or baking;
  • Avoid alcohol and caffeinated coffee;
  • Avoid salt that has a corrosive action on the intestinal mucosa;
  • Eat foods with probiotic action, such as lactose-free white yogurt, natto, miso and kefir or supplements with probiotic and prebiotic action;
  • Eat blue fish, rich in omega 3-4 times a week.