Lactose intolerance

When milk sugar makes you sick

For millions of people, milk is no benefit but a trigger for abdominal pains, diarrhoea and physical discomfort. This means, they are suffering from lactose (milk sugar) intolerance. As an enzyme is missing or produced too little, this is causing unpleasant and painful symptoms in people concerned. For many, this is a torture, especially when the intolerance remains undetected. However, not all of them have to renounce lifelong at milk, ice cream and Co. The severity of the intolerance varies from person to person and can be determined by a few simple tipps. Even in case of severe intolerance, there are lots of alternatives which enable you to enjoy milk based products. However, the food industry often plays a trick on us and misleads us by labelling lots of products lactose-free - even if they are poor in lactose by nature! Does everybody need lactose-free products? What are the benefits of the numerous lactose-free products? We tell you how to determine the reasons for your symptoms, whether you suffer from lactose intolerance and give you an overview of products which are lactose-free by nature. What does life with lactose intolerance look like? Which foods may be eaten? Never again cheese, milk and yoghurt? One thing is clear: People concerned must change their diet. The daily nutrition plan includes lactose-free products. With a heavy heart, milk, cream, yoghurt, curd and some cheeses may not be eaten anymore. Did you know that some cheeses are poor in lactose by nature and may therefore be consumed by lactose-intolerant people?

In this article, you learn more about milk sugar, what happens in your body when you are lactose intolerant and above all, how you notice it. Other contents based on latest scientific findings, are: symptoms, reasons and detailed therapy. Finally, we answer the questions about the correlation of lactose intolerance with diseases like diabetes, acne, asthma and depression by example of current studies.

What is lactose?

Lactose resp. milk sugar is a disaccharide which consists of glucose (grape sugar) and galactose. Lactose can be found mainly in milk of mammals and derived milk products such as cheese, curd and cream cheese. The lactose content varies according to the production process. Hard cheeses contain less lactose than cream cheese as lactic acid bacteria break down lactose. [1]

Lactose intolerance test

What is lactose intolerance?

Lactose intolerance is the inability to absorb lactose (= milk sugar). For intestinal processing, this milk sugar must be broken down into its chemical components. This is done by means of lactase - an enzyme. In case of lactose intolerance, this enzyme is lacking completely or partly. Due to this, lactose cannot be broken down and utilized. This causes gastro-enteric symptoms. [1]

In the following, you can find a detailed description of the biochemical process of lactose intolerance in simplified form:

Causes of the symptoms – The ‘coal factory’

Imagine the gastrointestinal tract as a coal factory. Instead of coal, lactose is processed and instead of employees there is the enzyme lactase. The tons of coal are shredded on a conveyor belt by sufficient and motivated staff. Only then, the colleagues at the next workstation have enough work. This process creates by-products - harmless gases. If, however, all or part of the workers are missing, the shredding does not take place. The coal pieces are transported as rough pieces to the next workstation. As the machines are running at high speed, they produce lots of by-products - the gases. Then, all people in the factory cough, pant and suffer from complaints. This resembles the lack of lactase in the small intestine. Lactose is not broken down into glucose and galactose and is transported uncleaved into the large intestine. The colonic bacteria utilize the unchanged lactose and produce hydrogen, methane and short-chain fatty acids. Carbon dioxide is causing flatulences and bad breath. The fatty acids take water from the intestine and dilute the stool - which results in diarrhoea. The amounts of gases cause bowel sounds, tiredness and heartburns. [3]

Types of lactose intolerance

There are several reasons why the body produces less or no lactose degrading enzymes. In general, the production of these enzymes declines with age. One explanation is the supply of mother’s milk from the cradle. The human body produces enough lactase during this time. Once the consumption of mother’s milk is stopped, lactase production starts to decrease. This physiological lactase deficiency (= hypolactasia) is widespread throughout the world. Further less common reasons are: [2]

Primary lactase deficiency: This is a genetic lactase deficiency and the production of lactase is drastically reduced by birth. This type of deficiency is very rare. If this disease is not treated at an early stage, it can cause growth and developmental disorders in children. [2]

Secondary lactase deficiency: This is the result of an underlying illness. The lactase deficiency is caused by a damage to the mucous membrane by e.g. Coeliac disease or inflammatory intestinal diseases such as Crohn’s disease or ulcerating colitis. Therefore, this type of deficiency can begin at any age. When the symptoms of the underlying disease can be alleviated, the symptoms of lactose intolerance mostly decrease as well. [2]

Milk allergy = lactose intolerance?

Again and again, those two terms are lumped together as milk is the trigger of the symptoms for both of them. But more milk protein allergy and lactose intolerance don’t have in common. In case of an allergy, the immune system is involved. Lactose intolerance, however, is caused by a missing or defective enzyme production without participation of the immune system.

Lactose intolerance – Symptoms

How to tell if you are lactose intolerant?

Symptoms of lactose intolerance are relatively clear. After drinking a glass of milk, the following gastrointestinal complaints appear: [1]

  • flatulence
  • diarrhea, constipation
  • stomach cramps, stomach pains

Headaches and migraine with nausea and vomiting can be further unspecific symptoms.[1]

Good to know:

As the uncleaved lactose is transported to the large intestine and is decomposed in it, this can cause bad breath. One reason is the large production of methane and carbon dioxide. If methane is exhaled, this causes bad breath. [1]

When do symptoms of lactose intolerance occur?

When exactly symptoms occur depends on the activity of the lactase. Maybe your stomach makes itself felt by loud sounds just 30 minutes or a few hours after consumption of foods containing lactose. [3]

Good to know:

Not only in case of an intolerance lactose can cause diarrhoea. Large quantities of foods containing lactose can have laxative effects even in people with normal lactase activity.

Can lactose intolerance give you skin problems?

A sip of milk or a bit size piece of cheese and your skin suddenly reddens and itches? When the itchy spots worsen after consumption of dairy products, lactose intolerance is suspected by people concerned. However, milk intolerance mainly affects the gastrointestinal tract. However, milk can still be a trigger. In this case, a milk allergy can be suspected. Therefore, a possible milk allergy should be considered in case of skin problems. Lactose intolerance makes the stomach cry out but not the skin itch! [4]

Lactose intolerance – Causes

What are causes of lactose intolerance?

The causes of lactose intolerance depend on the type of lactose intolerance. It is clear that too low production of lactase in the small intestine causes unpleasant gastrointestinal symptoms. The intensity of the symptoms is very individual and depends on the level of the intolerance. In other words: how much lactase is still produced and how much lactose is consumed.

Human lactase decline

One thing is certain: The body’s own production of lactase in the small intestine drops in infants as of the start of weaning. The body hereby adapts to the ingested food. Infants are world champions in milk-drinking without symptoms. Do not confuse the burps after nursing with symptoms. Babies produce lactase so they can break down mother’s milk and utilize it. As of the introduction of supplementary feeding, the activity and production of lactase drops. In how far it drops, varies from person to person.[2]

Damages to the mucous membrane by e.g. Coeliac disease or inflammatory intestinal diseases such as Crohn’s disease or ulcerating colitis can be another reason for the decline of lactase production. Such diseases can impair the production and activity of lactase. [2]

Good to know:

If a child cannot tolerate milk, it might have a milk allergy. This occurs especially in early childhood.

The role of genetics

There is a theory that lactose intolerance could be genetically determined. Especially Asians and South Africans suffer from lactose intolerance. Europeans and North Africans, however, can enjoy their glass of milk in the morning. But why?

There is a correlation to the beginning of settling of the formerly nomadic population and to the introduction of farming. As mankind at that time lived together with dairy cows and drank a lot of milk, they started to produce lactase. Milk served as a staple food which is why people in the North tolerate milk much better than people in the South. The following figures on the prevalence of lactose intolerance underline this hypothesis.[5]

Incidence of lactose intolerance

Worldwide, 75 percent of adults are affected by lactose intolerance. In Germany, 15-20 percent are unable to digest lactose contained in foods. What’s most eye-catching is the north-south divide, especially in Europe. In Northern Europe, less people suffer from lactose intolerance than in Southern Europe.[2]

In Sweden, only 5 percent of the population are affected, whereas in Southern Italy 68 percent of the population suffer from this intolerance. Asians hardly or not tolerate milk. In Japan, up to 98 percent of the population suffer from this intolerance. [2]

Lactose intolerance – Therapy

If you are diagnosed with lactose intolerance, you first have to renounce at foods containing lactose. Depending on the intensity of the symptoms, foods containing lactose can be added to your diet in small amounts. Please read on to learn how to integrate foods containing lactose into your diet without causing symptoms.

How to treat lactose intolerance

The correct treatment of lactose intolerance depends on the severity of the intolerance. This will determine to which degree the person concerned has to reduce or even avoid the consumption of lactose. If the intolerance is caused by an underlying disease such as Coeliac condition, the focus has to be put on it (secondary lactase deficiency). Otherwise, you can follow the subsequent steps for treatment of lactose intolerance.[3]

After diagnosis, follow these steps: Treatment of primary lactase deficiency requires changes in nutritional habits. This means that foods containing lactose must be eliminated from your diet. The change takes place in three steps. As a first step, the elimination of lactose relieves the strain on your digestive system. In the next step, the remaining lactase activity and the individual tolerance threshold are determined. Then you slowly explore how much lactose you tolerate.

1st phase: Lactose abstinence
Lactose abstinence means to completely renounce at lactose. For a maximum period of 2 weeks, you introduce a diet strictly poor in lactose. Moreover, you avoid sugar alcohols (sorbitol, xylitol, maltitol, mannitol and isomalt), which also cause symptoms. The aim is to eliminate symptoms as far as possible. A light normal diet is recommended. It contains legumes, cabbage, fried foods, onions and highly processed and spiced foods. [6]

2nd phase: Test phase

During this period, foods containing lactose (incl. milk and dairy products) are gradually re-introduced into the diet. This way, the individual tolerance threshold can be determined. You start with very small amounts of those foods and gradually increase them. This test is stopped when first symptoms occur. The aim is to find out your tolerance threshold. This way, you know exactly how much milk and dairy products you tolerate and don’t have to renounce lifelong at foods containing lactose.

3rd phase: Permanent diet

The third and last phase is considered as the determination of your permanent diet. Particular attention should be paid to the supply nutrients. It is best to check which foods have a high lactose content. People with reduced lactase production must avoid even small quantities of lactose and follow a strictly lactose-free diet. Most people concerned do not have to follow such strict diet as their lactase production normally is not that low. In case of a moderate lactose intolerance, up to ten grams lactose per day can be tolerated.

Practical experience has shown that the consumption of small amounts of lactose (less than 3 g) seldom causes reactions. Foods with low lactose content can mostly be consumed without problems. Symptoms often occur when more than 10 g lactose are consumed!

Selected foods

Content of milk sugar in g/100g

Cow’s milk


Curd (low-fat)


Plain yoghurt


Yoghurt (with skimmed milk powder)


Processed cheese (cuttable)


Cream cheese



During the change in diet, it is possible to take up the enzyme lactase in the form of tablets or capsules. You have to take them before you consume foods containing lactose. Whether they have a positive effect or not, varies from person to person. First, you have to determine the right dosage to avoid complaints. Lactase tablets should, however, only be taken in exceptional cases as the constant use of these tablets reduces the remaining lactase activity in your body. As a result, foods containing lactose are less well tolerated than before the test phase. People who are lactose intolerant should instead change their diet so that their colon can recover.

Reduction of symptoms

Symptoms of lactose intolerance start to improve after two weeks of lactose-free diet. During this time, the damaged mucous membrane of the small intestine recovers. However, the inherited (genetic) type remains a permanent condition. The necessary lactase is missing lifelong. However, also in this case, problems can be reduced by curing the underlying disease. [7]

Which foods you should avoid

Lactose is above all contained in milk and dairy products such as curd, cheese, cream cheese, mozzarella and yoghurt. Apart from cow’s milk, sheep’s milk, goat’s milk and mare’s milk also contain lactose and must be avoided as well.

Foods with a high lactose content are listed below. In case of a mild form of lactose intolerance, these foods can be eaten in smaller amounts. You have to individually test how strong your intolerance is. Start with very small amounts and gradually increase them. When gastrointestinal symptoms reoccur as of a certain amount, you should stop consumption. This way you can find out the limit of your individual tolerance. A nutrition diary can be helpful.

The German nutrition and information center (DEBInet) has published a list of foods containing varying amounts of lactose:

Food group

Foods containing lactose

milk / dairy products

Milk, cheese, dry milk, pudding, mixed drinks, hot chocolate, desserts, coffee whitener, condensated milk, cream, sour cream, sour milk, kefir, yoghurt, curdled milk, whey, curd, cottage cheese, processed cheese, cheese preparations

Bread / bakery products

Milk and/or milk powder can be contained in: bread and cake baking mixtures, milk rolls, waffles, cakes, cookies, crispbread, crackers

Ready meals

Pizza, frozen prepared dishes, preserves


Ice cream, chocolate, toffees, cream toffees, chocolate bars, nougat, hazelnut spread, candies

Meat / cold meats

Sausages, liver sausage, fat-reduced cold meats, sausage meat

Instant products

Instant soups, instant sauces, instant cremes, potato mash powder, dumpling flour, patty mixtures

Ready-made sauces

Gourmet and barbeque sauces, salad dressings, mayonnaise

Further products

Muesli mixes, margarine products, spreads

Which foods you can eat

Apart from the lactose-free food alternatives that are offered in vast amounts, there are lots of foods that are lactose-free by nature. Should you have to / want to resort to foods containing lactose, lactase tablets are a suitable alternative.

Even if the market for lactose-free products is booming, you do not necessarily have to replace all dairy products by lactose-free alternatives. Some cheeses and butter are poor in lactose. The following cheeses can be consumed symptom-free: [8]

  • Appenzeller cheese
  • Emmental cheese
  • Cheddar cheese
  • Mountain cheese
  • Parmesan cheese

The softer the cheese, the more lactose it contains. Mozzarella e.g. contains 3 g lactose per 100 g. Gouda cheese with 45% fat, however, contains less than 0.1 g lactose and belongs to the lactose-free products. [9]

All products with less than 0.1 g lactose per 100 g may be called / labelled

Low-fat curd is considered to be a top fitness-snack after training. It is a trusted companion not only for bodybuilding, but also for weight loss! But attention: It contains approx. 3 g lactose. In the cooling shelf, you can also find lactose-free low-fat curd. It lets the pounds roll off and the muscles grow in spite of lactose intolerance. [9]

Fun Fact:

80% of people buying lactose-free products do not suffer from an intolerance. There is a myth that lactose-free foods are healthier. Lactose-free foods are no “wonder weapon” for a healthier lifestyle. Whether or not foods contain lactose does not contribute to a healthier life without intolerances! [10]

Lactose intolerance and calcium

Everyone knows the slogan that milk contributes to maintaining stable and strong bones. The reason: milk contains calcium which is vital for the construction of bones and teeth, for muscle contraction and blood clotting. Calcium deficiency causes disturbances of the micro-architecture of bone tissue such as osteoporosis, caries, heart problems and problems of stimulus conduction [11] In case of lactose intolerance, calcium is a critical nutrient if no alternative calcium sources are supplied to the body.
Did you know why lactose-free milk tastes sweeter? Lactose-free milk contains the enzyme lactase. Thus, the lactose of the milk is already split up into its components. The sugar molecules glucose and galactose are available as free substances. Therefore, lactose-free milk has a sweeter taste than conventional milk.

Tips for (grocery) shopping

According to the EU directive (2007/68/EG), food producers are obliged to state in the list of ingredients whether or not lactose is contained. Therefore, people concerned should always carefully study the list of ingredients. This legislation is only valid for packed foodstuffs. Products with the declaration “May contain traces of milk components” are harmless.

For unpacked foodstuffs, we recommend to ask the manufacturer or seller e.g. in an ice-cream parlour. Nobody would like to eat his ice cream in summer with stomach pains. Sorbets could be an alternative. You must also be careful with medicines as these could also contain lactose. Many manufacturers meanwhile declare on their own whether their products are lactose-free - sometimes in the form of a seal, sometimes clearly visible in the form of a word. [11]

The following tips help you simplify your everyday life with lactose intolerance:

  1. Not only cow’s milk contains lactose but also goat’s milk, sheep’s milk and mare’s milk.
  2. You can better tolerate dairy products by distributing them over the whole day and by eating them together with a meal.
  3. Don’t leave out cheese because of your lactose intolerance. Its calcium content is vital for your nutrient balance. As a general rule: the older the cheese, the less lactose it contains.
  4. Fermented milk products such as kefir and yoghurt are better tolerated as their lactic acid bacteria break down lactose.
  5. You should eat calcium-rich vegetables like kale, leaf spinach and broccoli to optimize your calcium supply. Also use the cooking water of these vegetables.
  6. Avoid, if possible, sugar alcohols such as sorbitol, mannitol, xylitol. Larger quantities have laxative effects which are accompanied by flatulences and diarrhoea.
  7. Medicines can contain lactose. The lactose content is, however, very small and normally does not cause complaints. If necessary, you can resort to lactose-free alternatives. Please consult your doctor or pharmacist before a change.
  8. Make sure to drink at least 1.5 l per day. In case of diarrhoea, the requirement is even higher and should exceed 1.5 l. Prefer drinking or mineral water, unsweetened fruit or herbal tea and diluted fruit juice (spritzers with 3 parts water and 1 part juice).
  9. Prefer calcium-rich mineral waters.
  10. Psychological strains such as stress or anger can impair digestion. Take your time and enjoy your meal.
  11. Last but not least: Carefully check the list of ingredients! This may change at any time. Products with the inscription “May contain traces of milk components” can be eaten as their lactose content is very small.

Lactose intolerance – Test

Even if symptoms of lactose intolerance are very clear and occur directly after consumption of milk and dairy products, a lactose test creates clarity and, above all, security. Leaving out foodstuffs without any foundation can quickly lead to nutrient deficiencies. The Lactose Intolerance Test is pain-free and doesn’t require blood sampling as it is a breath test. We have summarized the details of this test method for you in the following.

Diagnostics – The cerascreen® Lactose Intolerance Test

Diagnosis of lactose intolerance is literally only a breath away. The proof is done via breath sampling (H2 breath test). The breath test measures hydrogen and methane. The H2 breath test is the gold standard method for diagnosis of lactose intolerance. After drinking a liquid solution containing lactose, breath samples are taken after several intervals. The concentrations of hydrogen and methane are measured in these breath samples, as these are produced in case of an intolerance. [12]

Why cerascreen® also measures the concentration of methane

As approx. 35 % of people do not exhale enough hydrogen, the methane concentration is also measured in the exhalation air. Methane is another breathing gas which is produced in greater quantities in case of an intolerance.

Lactose tolerance testing explained

A lactose intolerance test is intended for the determination of lactose intolerance, also called milk sugar intolerance. The cerascreen® Lactose Intolerance Test is a self-test for use at home. The test measures the concentration of hydrogen and methane in your exhaled breath. The intestine produces these gases in case of lactose intolerance in great quantities after consumption of foods containing lactose.

How to test for lactose intolerance

For diagnosis of lactose intolerance, you first have to drink a liquid solution containing lactose. The cerascreen® Lactose Intolerance Test requires breath sampling every 30 minutes until 5 samples have been taken. It is important to fast for these 3 hours. After sample taking, you send the samples to our laboratory so they can measure the hydrogen and methane concentration.

Where to test for lactose intolerance?

The lactose intolerance test can be done by your family doctor or allergist. These doctors also use breath tests. The execution is nearly identical with the cerascreen® Lactose Intolerance Test . In addition, the cerascreen® test also measures the methane concentration in order to guarantee analysis as per gold standard. Doctors mostly only measure the hydrogen concentration.

How long does the lactose test take?

The lactose intolerance test takes - depending on the number of samples required - up to three hours. During this period, fasting is required. The cerascreen® Lactose Intolerance Test requires five breath samples to be taken every 30 minutes. The test takes three hours. Preferably, you should stay at home for it. When doing the test at the doctor’s, you have to stay there the whole time. In case of an intolerance, symptoms depending on the severity of the intolerance occur.

Lactose intolerance – measured values

When evaluating the lactose intolerance test, the differential values of the measured concentrations of exhaled hydrogen and methane and of the fasting values are calculated. The samples are taken every 30 minutes after consumption of the liquid solution containing lactose. If the hydrogen analysis shows a difference of 20 ppm (parts per million) and/or for methane of 12 ppm, lactose intolerance is very likely. If the methane concentration is smaller, the result of the hydrogen analysis is the decisive parameter.

Example of exhaled breath analysis

hydrogen analysis

difference after 30 minutes

8.0 ppm

difference after 60 minutes

22.0 ppm

difference after 120 minutes

7.0 ppm

difference after 180 minutes

0.0 ppm

Is there a difference of at least 20 ppm?    Yes

Methane analysis

difference after 30 minutes

3.0 ppm

difference after 60 minutes

10.0 ppm

difference after 120 minutes

12.0 ppm

difference after 180 minutes

14.0 ppm

Is there a difference of at least 12 ppm?    Yes

Lactose and diabetes

At first glance, lactose intolerance and diabetes don’t seem to have anything in common. In practice, however, diabetics often mention symptoms which suggest lactose intolerance: flatulences, constipation and / or diarrhoea.

Scientific findings

In 2016, a large-scale study showed a correlation between diabetes mellitus type 2 and lactose intolerance. The study compared the presence of lactose intolerance in diabetes patients with healthy participants and resulted in the following finding: Considerably more diabetics are affected. Why lactose intolerance occurs more often and whether there is a correlation with insulin, has not yet been clarified. [13]

In another study scientists showed that the renouncing of dairy products increases the risk of diabetes mellitus type 2. The reason: calcium-deficiency. Study participants who consciously renounced at milk products showed a significantly increased risk to develop diabetes type 2. They renounced at milk and milk products as they suspected to be lactose intolerant. However, this assumption was not based on diagnosis by a doctor or by a lactose intolerance self-test. [14]

The conclusion of the author of the study: For securing the diagnosis of an intolerance you should consult a doctor or do a lactose intolerance self-test.

Good to know:
Diabetics have to take into consideration the consumption of foods containing lactose for the calculation of their insulin dose. Lactose, a milk sugar, is normally broken down into its components glucose and galactose. Glucose causes a rise in blood sugar levels. Diabetics have to counter this rise with insulin. Milk products which do not contain added sugar (plain yoghurt), ensure that blood sugar levels rise slower. [15]

Conclusion - the current state of science

Lactose intolerance does not favour the occurence of diabetes mellitus type 2. But the conscious renouncing of dairy products due to self-diagnosed lactose intolerance can cause calcium deficiency. Calcium deficiency can, however, increase the risk of diabetes-diseases. Therefore, a suspected lactose intolerance should by all means be clarified.

If you feel complaints after consumption of certain foodstuffs, do not avoid them. Consult a doctor or do a self-test to determine whether you have an allergy or intolerance. Self-diagnosis can lead to nutrient deficiency!

Lactose and acne

Milk products are suspected to be associated with the development of acne and pimples. Whether there really is a correlation, is not clear considering recent studies. The hormones and proteins contained in milk are suspected as triggers for impure skin. Thus, there is no direct correlation between lactose intolerance and skin impurities. Blemishes caused by milk are more often caused by milk allergy. [16]

Lactose and depression

A survey has in fact shown a correlation between lactose intolerance and depression. The survey participants were women who filled in a questionnaire for determining a depression. The evaluation showed that women with lactose intolerance had a stronger tendency towards depressions than healthy women - due to the impairement of a certain amino acid (L-tryptophan). The main task of this amino acid is to bring happiness as it is transformed by the body to serotonin. [17]

Conclusion: Indeed, the study showed a reduced production of an amino acid which influences our emotional state - a general statement can, however, not be made and recommendations for action cannot be given.

Lactose and asthma

The complaints caused by lactose intolerance are mainly referring to the gastrointestinal tract. Thus, lactose intolerance does not promote asthma diseases. Here, too, the follwing rule applies: If you feel respiratory problems after consumption, you should do a test for milk allergy[12]


  • Lactose is a disaccharide which is broken down by the body for further transportation in blood.
  • This chemical cleavage is done by the enzyme lactase which is produced in the small intestine.
  • Lactase deficiency leads to insufficient or missing cleavage - which is called lactose intolerance.
  • Deficiency or absence of lactase can be congenital or caused by an underlying disease.
  • Lactase production decreases with age.
  • In Europe, there is a north-south divide. In Northern Europe, less people suffer from lactose intolerance than in Southern Europe.
  • Symptoms of lactose intolerance are flatulence, stomach cramps, stomach pains, diarrhoea and constipation.
  • Treatment of lactose intolerance starts with a diet free of lactose. Then, by and by, foods containing lactose are re-introduced.
  • Hard cheeses such as Emmentaler cheese but also butter are normally well tolerated. Supermarkets meanwhile offer lactose-free alternatives for milk, cream, curd, yoghurt and soft cheeses.
  • To confirm lactose intolerance, the hydrogen concentration in exhaled breath is measured. For this, a liquid solution containing lactose must be drunk.
  • Skin problems are not associated with lactose intolerance. They are rather attributed to the hormones and proteins contained in milk or to a milk allergy.

Reference list 

  1. Laktoseintoleranz: Nicht alle Milchprodukte unverträglich,
  2. Laktose-Intoleranz - Milchzucker-Unverträglichkeit - Laktasemangel - BGV Info Gesundheit e.V.,
  3. Kasper, H.: Ernährungsmedizin und Diätetik. Urban & Fischer Verlag/Elsevier GmbH (2014)
  4. Lactose Intolerance vs. Dairy Allergy,
  5. Absence of the lactase-persistence-associated allele in early Neolithic Europeans | PNAS,
  6. Rationalisierungsschema,
  7. Treatment,
  8. Hartkäse und Weichkäse - Lebensmittel-Warenkunde,
  9. Die Zusammensetzung der Lebensmittel, Nährwert-Tabellen. (2016)
  10. “... frei von Laktose” - BZfE,
  11. EU03_2010_markt_produkte.qxd.pdf,
  12. Laktose-Intoleranz: DAAB,
  13. Rana, S., Morya, R.K., Malik, A., Bhadada, S.K., Sachdeva, N., Sharma, G.: A relationship between vitamin D, parathyroid hormone, calcium levels and lactose intolerance in type 2 diabetic patients and healthy subjects. Clin. Chim. Acta. 462, 174–177 (2016). doi:10.1016/j.cca.2016.09.009
  14. Gao, D., Ning, N., Wang, C., Wang, Y., Li, Q., Meng, Z., Liu, Y., Li, Q.: Dairy Products Consumption and Risk of Type 2 Diabetes: Systematic Review and Dose-Response Meta-Analysis. PLoS ONE. 8, e73965 (2013). doi:10.1371/journal.pone.0073965
  15. Frühstück: So schaffen Sie eine gesunde Grundlage,
  16. Melnik, B.C.: Evidence for Acne-Promoting Effects of Milk and Other Insulinotropic Dairy Products. Milk Milk Prod. Hum. Nutr. 67, 131–145 (2011). doi:10.1159/000325580
  17. Ledochowski, M., Sperner-Unterweger, B., Fuchs, D.: Lactose malabsorption is associated with early signs of mental depression in females: a preliminary report. Dig. Dis. Sci. 43, 2513–2517 (1998)