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Facts and advice about lactose intolerance in children – written by a pediatrician. No children are lactose intolerant at birth. At school age, a child who is lactose intolerant gets diarrhea and a stomach ache from drinking milk.
Lactose is “milk sugar”
Lactose is a sugar found in milk. A lactose molecule is made up of two sugar molecules that are chemically joined together. In order for the intestine to absorb the sugar into the blood, an enzyme called lactase must divide the sugar molecule into two.
Milk also contains milk proteins. Cow’s milk protein allergy is a fairly common disease in young children that should not be confused with lactose intolerance.
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Lactase is found in the intestinal lining
The small intestine is the part of the intestine where the mucous membrane absorbs nutrients. In order for the mucous membrane to absorb as much nutrition as possible, it has maximized its surface area by being ‘fuzzy’. At the far end of the intestinal lining is the lactase enzyme.
Celiac disease, or gluten intolerance, is a disease that destroys the intestinal lining. An untreated gluten intolerance therefore leads to lactose intolerance. Therefore, it is important to test children for gluten intolerance if they develop symptoms of lactose intolerance. This becomes more important the younger the child is.
Lactose in the colon causes diarrhea
When lactose is not broken down in the small intestine by lactase, it is transported to the large intestine. The bacteria in the colon have enzymes that can break down lactose in slightly different ways. As residual products, the bacteria form gases, both foul-smelling and odorless. In addition, lactose retains fluid in the stool, and therefore the poo becomes loose ie. diarrhea. The symptoms of lactose intolerance are therefore, gas formation, diarrhea, and often stomach pain that occurs some time after a meal if the meal contained lactose.
Babies are not lactose intolerant
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It is extremely unusual for a baby not to have lactase. Forty babies in total with this condition are described in scientific literature. Babies who do not have it get severe diarrhea as soon as they start drinking breast milk or formula. With the exception of these very few babies, all babies have lactase, and are lactose tolerant, until two years of age.
Lactose intolerance is normal
About two-thirds of the world’s population stop producing lactase during childhood. Therefore, lactose intolerance in older children and adults is a normal condition. This usually happens after the age of seven, but it differs between different ethnic groups. The production of lactase decreases slowly, so stomach problems that come on suddenly are not usually due to lactose intolerance.
In Scandinavia, we have a “genetic anomaly”. That means that most of us who have Scandinavian origins many generations back in time, continue to produce lactase and can eat unlimited amounts of lactose throughout life.
Blood tests for lactose intolerance
The blood tests that are available for lactose intolerance are genetic tests that show whether you have the variant that often becomes lactose intolerant as an adult, or the one that rarely becomes one. So they do not say whether you can tolerate lactose or not. To know that, you have to eat lactose. If you get the typical symptoms of lactose intolerance, and it disappears with a lactose-free diet, you are probably lactose intolerant.
Lactose intolerance is not dangerous
Lactose does not harm the intestines or the body of those who are lactose intolerant. The symptoms are just unpleasant, not dangerous. Often people with lactose intolerance can eat a certain amount of lactose without symptoms, and this is what you should do. Avoid problems.
Lactose-free dairy products
In lactose-free dairy products, lactase is added to the dairy products. The lactase enzyme breaks down the milk sugar in the milk package before consumption. They are more expensive than ordinary dairy products and have no advantage whatsoever for anyone who can produce lactase. Additionally it’s not in any way dangerous to your health even if you produce your own lactase. There are also tablets with lactase (Lactrase) available at the pharmacy. You can take these tablets when you want to eat more dairy products than you usually manage, without getting symptoms.
Foods that do not contain dairy products also do not contain lactose.
Read more:
Läs mer om mjölkproteinallergi hos bebis och mjölkfri ersättning till spädbarn
Läs mer om magsjuka eller vinterkräksjuka hos barn – smitta, inkubationstid
Läs om glutenintolerans eller celiaki hos barn