Lactose Intolerance - Everything On The Topic

Table of contents:

Lactose Intolerance - Everything On The Topic
Lactose Intolerance - Everything On The Topic
Video: Lactose Intolerance - Everything On The Topic
Video: Lactose intolerance - causes, symptoms, diagnosis, treatment & pathology 2023, February

Lactose intolerance

Lactose, the main carbohydrate of any milk, whether animal or human, consists of two individual sugars and is normally digested in the small intestine into glucose (single sugar, dextrose) and galactose (single sugar, mucous sugar). Incorrect digestion leads to complaints that can vary in severity. Some sufferers get severe discomfort even with the smallest amounts. Usually, however, small amounts of lactose are well tolerated.


  • Continue reading
  • more on the subject
  • Advice, downloads & tools
  • What are the causes of lactose intolerance?
  • What are the symptoms of lactose intolerance?
  • Lactose in Food
  • How is the diagnosis of lactose intolerance made?
  • How is lactose intolerance treated?

What are the causes of lactose intolerance?

In the event of an intolerance, the lactose is not or only insufficiently broken down because the responsible enzyme lactase is lacking. The lactose therefore reaches the large intestine (colon) undigested. There it is broken down by bacteria into lactic acid and acetic acid as well as intestinal gases (hydrogen, carbon dioxide) - this causes symptoms.

  • A so-called primary lactose intolerance can be hereditary and exist from birth or develop gradually. It begins with the very first contact with lactose, usually in infancy when breastfeeding, because breast milk also contains lactose. In Europe, around 15 percent of the population are lactose-intolerant, in Afro-Asian regions over 85 percent. It is assumed that tolerance in Europe represents an evolutionary adaptation to the dairy culture. Because of physical immaturity, premature babies are more prone to lactose intolerance, which can be temporary because enzyme production can ripen.
  • A so-called secondary lactose intolerance is the result of another disease. For example, in the case of an original gluten intolerance, the mucous membrane of the small intestine, where the lactose-breaking enzyme lactase is located, is severely damaged. However, this damage is reversible, ie it recedes when the intestinal mucosa heals; the tolerability of lactose thus improves again. In addition, secondary lactose intolerance can occur in other intestinal diseases such as chronic inflammatory bowel diseases (e.g. ulcerative colitis, Crohn's disease) or gastrointestinal infections.

What are the symptoms of lactose intolerance?

About one to two hours after a meal containing lactose, the following symptoms can occur:

  • Flatulence,
  • Stomach pain,
  • Diarrhea,
  • possibly nausea and vomiting.

Non-specific complaints such as tiredness or general malaise can also occur.

Lactose in Food

The lactose content of certain foods:

  • Lactose-free: are all foods that do not contain any milk or dairy products, e.g. soy products, plant-based milk powder, margarine, meat, eggs, cereals, potatoes etc.
  • Almost lactose-free (less than one gram of lactose / 100 grams): e.g. butter, rice, coconut and oat milk, hard, semi-hard and soft cheese.
  • Medium lactose content (one to 4.5 grams of lactose / 100 grams): e.g. curd cheese, cottage cheese, sour milk and cream, buttermilk.
  • Higher or high lactose content (over 4.5 grams of lactose / 100 grams): e.g. milk, whey.

A list of foods and their exact lactose content can be found at the Association of Diaetologists Austria.

Lactose can also be found in the following ingredients or products:

  • Milk bread, cakes and tarts,
  • Baking mixes,
  • Breadcrumbs,
  • Ice,
  • Mashed potatoes e.g. powder,
  • Ketchup, mustard, mayonnaise,
  • Ready meals and sauces,
  • Sweetener,
  • Sausages,
  • Medication.

Food labeling

According to the EU Consumer Information Regulation, milk and the products made from it (including lactose) must be labeled and highlighted in the list of ingredients, for example by means of font or background color. This extended labeling requirement has been mandatory for packaged and unpackaged goods (open, loose goods) since December 2014.

Further information is available from:

  • Ingredients in foods that are subject to labeling
  • EU rules on food labeling.
  • Brochure of the Chamber of Labor That belongs on the label. The new food information

How is the diagnosis of lactose intolerance made?

For many sufferers, it is a long way to a definitive diagnosis of lactose intolerance. As part of the anamnesis, it is clarified which complaints occur and which temporal connections exist with the consumption of certain foods. Various tests can then be carried out, including:

  • Lactose tolerance test (also called provocation test): A certain amount of milk sugar is dissolved in water and drunk. This is followed by a blood test at certain time intervals, during which the blood sugar level is measured. If the enzyme lactase splits milk sugar into its components glucose and galactose, the blood sugar rises. If the rise in blood sugar is too low, you are probably lactose intolerant. You can also observe the development of complaints.
  • H 2 breath test: If the lactose is not digested properly in the large intestine, hydrogen is produced, among other things. This is exhaled through the lungs and can be measured in the breath. In this test, depending on the question “lactose intolerance” or “fructose intolerance”, the hydrogen content (H 2) in the air is measured: first on an empty stomach; then after administration of a defined amount of lactose or fructose - several times at intervals of 30 minutes each (usually a total of 5 times). Only one of the tests can be performed in a day.

A nutrition and symptom log is also helpful, as this can establish certain connections between symptoms and the food consumed.

How is lactose intolerance treated?

If symptoms occur even with small amounts of lactose, a lactose-free diet should be followed. The intake of lactose should be limited to a maximum of one gram per day on this diet. If small amounts of lactose are tolerated, a low-lactose diet helps in many cases - eight to ten grams of lactose can be consumed per day. For comparison: with a normal diet, around 20 to 30 grams of lactose are consumed per day.

Pay attention to calcium intake

If you are on a lactose-free or low-lactose diet, pay particular attention to an adequate intake of calcium. It is found in high quantities in vegetables such as kale, broccoli, fennel, leek or spinach and in various mineral waters with a calcium content of more than 150 milligrams / liter. For more information on the calcium content, see the seasonal calendar for fruit and vegetables.

Dairy products with the lactose removed are often fortified with calcium. They can also help meet your calcium needs. Soy milk and products are naturally lactose-free. Rice, coconut and oat milk are low in lactose.

You can find more information under Calcium and in the information sheet on lactose from the social security agencies.

Various enzyme substitutes can support the digestion of milk sugar. They contain the enzyme lactase and are taken before meals. However, there is no scientific evidence for its effectiveness.

A balanced diet is also possible with lactose intolerance. Many foods are naturally lactose-free or low-lactose. The Austrian food pyramid should serve as the basis of nutrition. An adequate supply of calcium and vitamin D must be taken into account. Qualified nutritional advice is helpful.

For more information, see Nutritional Advice and Therapy.

Popular by topic