Milk makes you a fart

Determine lactose intolerance using a self-test

Lactose intolerance affects around 15 percent of Germans. You react to milk and many dairy products with gas, diarrhea and stomach pain. Four tests provide valuable information about an intolerance. One of them can be done at home. But it takes some courage.

In the case of lactose intolerance, those affected lack the enzyme lactase, which breaks down the milk sugar lactose in the intestine. Digestive problems are the result. The severity of the intolerance varies from person to person.

Lactose intolerance: four complaints

The most common complaints include gas, severe abdominal pain, diarrhea and nausea. Non-specific symptoms such as tiredness, headaches, dizziness, palpitations, itchy skin and night sweats are frequent companions of lactose intolerance.

Pure milk triggers the most violent reactions

"Some patients are sensitive to very small amounts, others can still tolerate 15 grams of lactose quite well," explains Kristin Mayr, Chairman of the Board of the Association for Lactose Intolerance (VLI). But they all have one thing in common: drinking a glass of milk is not good for either of them. "Milk triggers violent reactions because 100 milliliters already contain almost five grams of lactose," says Mayr.

After 15 minutes on the toilet

After just five minutes, many people feel their first symptoms. There is pressure in the abdomen and the intestines begin to grumble. "If a person concerned has exceeded their individual tolerance threshold, it drives them to the toilet after 15 minutes at the latest," says the expert. "The body wants to get rid of the problematic intruder as quickly as possible."

Only for the brave: self-experiment at home

If you repeatedly have digestive problems after certain meals and suspect milk as a trigger, you can try a self-test and drink a glass of milk on an empty stomach. But: "This is something for the brave," warns the expert. "If you have lactose intolerance, you have to be prepared for the fact that you will get severe symptoms and feel bad all day." You should therefore choose a day for the self-experiment on which you have time to cure the symptoms.

Complete waiver is usually not necessary

According to Mayr, it is better to see a doctor immediately if you suspect something. In addition to the actual diagnosis, it is also important to find out how pronounced the intolerance is. "Many people do without dairy products completely if they are suspected. That is a shame because there are some that are naturally lactose-free and can be eaten without hesitation even if they are severely intolerant."

Lactose intolerance: Butter is usually not a problem

Hard cheeses such as Parmesan or Emmentaler, for example, are completely lactose-free. Butter is low in milk sugar because it is very high in fat. According to the expert, yoghurt is also not a problem for most patients. How much lactose the body accepts varies from person to person. "It is important that those affected slowly approach their limits. That requires patience, but usually they are rewarded. Many are amazed at what they can tolerate despite lactose intolerance," Mayr knows from experience.

Breath test measures the proportion of hydrogen in the lungs

The doctor usually chooses the breath or the blood test to make the diagnosis of lactose intolerance. The genetic test is used less often. According to Mayr, the breath test is the most frequently performed test. To do this, the patient drinks a solution of 50 grams of lactose and 250 milliliters of water. Then he is put on a breathing mask, which evaluates the exhaled gases. The higher the proportion of hydrogen (H2) in the air, the more pronounced the intolerance is usually.

Breath test not always reliable

The hydrogen is produced when the lactose reaches the large intestine undigested and is broken down there by the bacteria. The gas enters the bloodstream via the intestinal wall and from there to the lungs. However, the result of this test is not always reliable. "There are few patients who do not exhale hydrogen, but other gases," explains Mayr. "Then the breath test can turn out negative, although there is an intolerance." If the test result does not indicate any intolerance, although the measurement resulted in diarrhea, flatulence and abdominal pain, the expert advises carrying out further tests.

Blood sugar levels reveal lactose intolerance

Another way to diagnose intolerance is to take a blood test. Here, too, the patient has to drink a lactose solution. Then six blood samples are taken and evaluated. In a healthy person, lactose is broken down into glucose and galactose in the small intestine. As a result, the blood sugar level rises. If this digestion step is missing because the enzyme lactase is insufficiently available, no increase can be detected.

Genetic testing works without a lactose drink

The advantage of a genetic test is that the patient does not have to drink a lactose solution, which saves him from having to go to the toilet. A swab is taken from the lining of the mouth with a cotton swab and sent to a laboratory. This is how the genetic predisposition to lactose intolerance is determined. "However, the genetic test can neither determine whether the intolerance has really broken out, nor how far the production of the enzyme lactase has already decreased," says Mayr. It only shows the predisposition for the intolerance.

Beware of hidden lactose

If the diagnosis of lactose intolerance has been made, it is advisable to seek nutritional advice. "If you are informed, you will be spared a lot of stomach ache," says Mayr. "Depending on how pronounced the intolerance is, hidden lactose in particular can become a real problem."

According to the expert, lactose is not only contained in many ready-made meals, but also often in sausage, food supplements, sweeteners or medicines. There is a reason for the frequent use of lactose: "Lactose is an ideal stabilizer and ensures a pleasant, full-bodied consistency. This is what makes it so attractive for the industry."

Important NOTE: The information is in no way a substitute for professional advice or treatment by trained and recognized doctors. The contents of t-online cannot and must not be used to independently make diagnoses or start treatments.