Lactose intolerance: symptoms and helpful tips


Cow's milk is facing more and more competition from plant-based milks. One of the main reasons for this is lactose intolerance, which affects one in five people in Switzerland.

What is lactose intolerance?

In order for our body to be able to absorb lactose into our blood via the intestines, it first has to separate the lactose in the small intestine into the two sugar components galactose and glucose. This is the job of the digestive enzyme lactase.

The missing enzyme lactase

People with lactose intolerance don’t produce this enzyme or produce it in insufficient amounts due to heredity factors or a disease. Instead of entering the bloodstream, the lactose passes undigested into the large intestine where it’s fermented by bacteria. The result is flatulence and diarrhoea.

Stress or unhealthy lifestyles can exacerbate the symptoms.

Symptoms of lactose intolerance

The fermentation of the lactose produces a lot of gas in the large intestine. The resulting accumulation of gas and water leads to symptoms such as

  • flatulence
  • stomach cramps
  • diarrhoea
  • nausea
  • wind
  • constipation
  • acidic stools (often leading to inflammatory skin conditions around the anus in children)

How many people suffer from lactose intolerance?

The most common food intolerances include histamine intolerance, gluten intolerance (coeliac disease) and fructose intolerance. With 15-20% of people affected by the condition, lactose intolerance is the most common food intolerance, not only in Switzerland but worldwide (not to be mistaken for a food allergy). The extent of the intolerance varies from person to person. Some people can tolerate a glass of milk, while others react to even small amounts. Lactose intolerance isn't life-threatening, but the symptoms are usually very unpleasant and put constraints on the person’s lifestyle.

Who suffers from the intolerance?

A baby naturally has the highest levels of lactase in order to easily digest the lactose in breast milk. As soon as the baby is no longer breastfed but receives another main source of food, lactase production decreases. The decrease varies from individual to individual and is genetically determined. Correspondingly, regional differences vary greatly too. In Scandinavia, the decrease is only about 3%, while in Africa and Asia almost 100% of the population has a lactase deficiency.

What foods contain lactose?

Normal milk contains the most lactose and is therefore the least tolerated. Milk powder, cream, cream cheese and ice cream are also among the foods containing the most lactose. But not all dairy products are poorly tolerated.

Products that are better tolerated

Sour milk products such as yoghurt contain less lactose than pure milk because the bacteria convert the lactose into lactic acid during lactic acidification. Butter and mature cheese are also well tolerated because they contain only small traces of lactose. In the latter, bacteria break down most of the lactose during the maturing process. Furthermore, the range of healthy dairy product alternatives on the market is steadily growing.

Lactose is usually hidden: read product packaging carefully

People who are particularly sensitive should read the declaration on the packaging. Lactose can also be found in soups, sauces, seasoning, bouillon, margarine, bakery products, meat products and ready-made meals as well as milk chocolate, cream sweets and drinks with milk serum such as red/green/blue Rivella.

Everyday tips

  • 12g of lactose per day is usually well tolerated. This corresponds to about 250ml of milk. If spread over the day and consumed with main meals, this is often not a problem.
  • Avoid industrially manufactured products, as they sometimes contain milk powder or lactose concentrates which can quickly amount to more than 12g of lactose.
  • Lactose is usually better tolerated when foods rich in fat or protein are eaten at the same time.

What helps with lactose intolerance?

People with lactose intolerance can usually tolerate certain amounts of lactose. After receiving the diagnosis, these people are therefore advised to first eat a mostly lactose-free diet for a short period of time and then move on to a test phase to determine their individual tolerance levels. The results must be discussed with a specialist (e.g. a nutritionist).

Taking enzymes in tablet form

If you often eat out and don't want to constantly check foods for lactose, you can also take the missing enzyme lactase in capsule or tablet form before eating. Because the enzyme works just like the body's own, there are no side effects.

Help for people with the condition

The aha! Swiss Allergy Centre works on behalf of the almost 3 million people in Switzerland who suffer from an allergy or intolerance. The aha! Swiss Allergy Centre offers free advice by phone from Monday to Friday (8.30 a.m. to 12:00 noon) on 031 359 90 50.

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