Lactose intolerance is caused by a deficit in lactase, the enzyme that allows the body to digest milk products. When lactose is not transformed into glucose and galactose by lactase, it ferments in the intestines, causing digestive discomfort. So what are the symptoms?
Lactose intolerance: the symptoms
The symptoms can vary from person to person, and they depend on the quantity of lactose absorbed. Here are the main symptoms reported by people who are lactose intolerant, which generally appear between 30 minutes and 2 hours after consuming products containing lactose:
- sensation of bloating,
- abdominal cramps,
- muscle and joint pains, etc.
In Europe, 30 to 50% of adults suffer from incomplete digestion of lactose. If you present with several of these symptoms or if one of them is very frequent or intense, consult your doctor.
What are the causes of lactose intolerance?
In infants, a deficit in lactase (and thus lactose intolerance) is less common. In young children, it is to do with a fairly rare condition: congenital lactase deficiency.
In children, a temporary intolerance to lactose can occur following gastroenteritis, for example, but it usually stops when the lining of the intestines heal.
In adults, the presence of lactase reduces gradually with age, which is due to a normal adaptation to dietary diversification, and not due to an illness.
For the majority of people who are lactose intolerant, their tolerance threshold is high enough to support moderate consumption of dairy products without causing any digestive symptoms (for example, one glass of milk per day).
Sometimes, lactose intolerance can be linked to a condition of the small intestine (celiac disease, gastroenteritis, giardiasis or Crohn’s disease) which can last several weeks, or until the intestines heal.
Lactose intolerance should not be confused with an allergy to milk proteins, which is more rare and more serious. This can cause digestive, respiratory and skin symptoms.
Lactose intolerance does not lead to risks of complications, contrary to an allergy to milk proteins.
How to avoid calcium deficiency?
People who are lactose intolerant can find sources of calcium in other foods, rather than dairy products. To help you out, here is a list of 30 foods that are rich in calcium.