Unlike cow’s milk protein allergy, with which it is often confused, lactose intolerance does not endanger the lives of patients at any time. It nevertheless causes serious digestive disorders, sometimes very painful. Update on lactose intolerance, its symptoms, causes and treatment.
With 20% of people affected , France is relatively spared from lactose intolerance which concerns between 80 and 100% of Asians. Rare in newborns, it usually appears after weaning, in parallel with the intensification of dietary diversification.
What is lactose intolerance?
Lactose is the main sugar in milk . It is found naturally in most dairy products , but at very variable contents, depending on whether they have undergone lactic fermentation or not: with 38 g per 100 g, powdered milk is the dairy product richest in lactose. , well ahead of skimmed or whole milk (5%) and ice cream (3 to 8%). Far behind, the cheeses, which contain between 0.1 and 2 g (camembert and gouda respectively).
To be digested, lactose must be split into two other sugars , the glucose and galactose ; it is lactase, an intestinal enzyme, which ensures this degradation.
Lactose intolerance is a digestive disorder caused by the absence or insufficiency of lactase . Lactose then arrives as it is in the large intestine where it is fermented by bacteria.
This process causes the production of fatty acids, gas (hydrogen, carbon dioxide and methane) and creates a call for water in the large intestine. This results in an acceleration of intestinal transit with diarrhea, gas and pain.
Symptoms of lactose intolerance
Lactose intolerance is manifested by digestive disorders :
- Flatulence ;
- Abdominal pain ;
- Diarrhea ;
- Bloating .
- Abdominal cramps,
- Nausea and / or vomiting ;
- But also by general symptoms:
Muscle and joint pain , etc.
Unlike cow’s milk protein allergy , with which it is often mistakenly confused , lactose intolerance does not affect other body systems (respiratory system or skin), nor does it affect it. does not cause complications .
These symptoms are however embarrassing and sometimes painful enough to require a diagnosis and management of patients suffering from lactose intolerance.
The severity of lactose intolerance varies greatly from person to person; but in the majority of intolerant people there remains a capacity to digest approximately 10 to 12 g of lactose , or a glass of milk.
Causes of lactose intolerance
There are two pathological causes of lactose intolerance:
A genetic mutation causing the absence of lactase, called primary alactasia ;
Destruction of the intestinal mucosa by various diseases ( cancer , gluten allergy, digestive diseases ), which, in fact, can no longer produce lactase. This is called secondary alactasia .
While lactose intolerance and the symptoms it causes are irreversible in primary alactasia , the disorder is only temporary in secondary alactasia , for a duration corresponding to that of the disease responsible for the disease. non-production of lactase.
In addition, lactose intolerance is the consequence of a perfectly physiological process, which occurs to a greater or lesser extent in nearly half of adults: the gradual decrease in lactase activity with age , which responds to an adaptation of the digestive system to food diversification . This drop in the activity of the intestinal enzyme leads to lactose intolerance, which is generally mild: most adults can indeed consume a bowl of milk without showing digestive symptoms of this disorder.
Diagnosis of lactose intolerance
A lactose weaning for a fortnight often makes it possible to incriminate or, on the contrary, to rule out lactose intolerance as the cause of its digestive disorders.
All you have to do is eliminate all products containing lactose from your diet and see if the symptoms disappear . This can be a delicate undertaking, however, given that lactose is used in the composition of many foods.
As the symptoms of lactose intolerance are not very specific, it may be useful to consult a gastroenterologist in order to rule out other diseases , such as irritable bowel syndrome , Crohn’s disease or even ‘ gluten intolerance . The specialist will then carry out a biological test which aims to measure the concentration of hydrogen in the exhaled air. “ The test takes about 4 hours. After absorbing a liquid containing 25 g of lactose, the person exhales into a mouthpiece every 30 minutes. Hydrogen produced by the large intestine and present in exhaled breath samples is analyzed. Aabnormally high concentration of hydrogen indicates that the body has not absorbed lactose and that the latter has fermented in the intestinal flora thus producing hydrogen “, explains the Health Insurance.
Lactose intolerance: what treatment?
Lactose intolerance is not treated as such. The management of patients suffering from lactose intolerance is based on the avoidance of products containing this sugar:
In particular dairy products,
But also foods for which lactose is used as a food additive : frozen bread, cereals, cold cuts, industrial vinaigrettes, preparations for cakes and cookies …
Also watch out for drugs , which are about 20% to contain lactose as an excipient.
The lack of lactase can, from time to time, be compensated by taking food supplements containing this enzyme . Consumed just before a meal, the enzyme contained in food supplements reaches the intestines at the same time as dairy products or foods containing lactose, allowing their assimilation .
Finally, there are products without lactose or low in lactose , to replace traditional dairy products.