Can lactose intolerance cause fatigue? Learn the symptoms here

Lactose intolerance is a serious food intolerance . It can cause numerous complaints and severely impair your enjoyment of life. In addition to gastrointestinal problems, lactose intolerance is also often the cause of fatigue, difficulty concentrating and other problems.

In general, it is a matter of the body reacting sensitively to lactose . A healthy, balanced diet is still possible because cow's milk and other dairy products can be easily replaced.

We provide you with comprehensive information about lactose intolerance and symptoms and offer solutions. You can get rid of symptoms such as fatigue caused by lactose intolerance by avoiding animal milk products!

Common symptoms of lactose intolerance

You can tell whether your body is reacting to lactose through many different symptoms. Physical complaints, mainly in the gastrointestinal area, but stressful signs such as fatigue are typical for sudden food intolerance.

If you or your child has lactose intolerance, the following physical symptoms may occur :

  • Bloated stomach
  • Feeling of fullness
  • stomach pain
  • loud bowel sounds
  • nausea
  • Diarrhea
  • constipation

Rarely, vomiting may also occur. Frequency and severity vary. How severe the individual symptoms appear depends on the degree of intolerance , which is very individual.

Some symptoms seem to contradict each other, for example diarrhea or constipation can alternate. In general, however, most of those affected suffer from discomfort that appears quickly after eating .

In the case of lactose intolerance, the symptoms vary in duration : some may appear immediately after eating foods containing lactose and disappear quickly, others torment you over a longer period of time.

Whatever else is stressful

Other physical impairments that can occur include headaches, dizziness, body aches, acne and cardiac arrhythmias. The trigger cannot always be clearly defined.

Lactose intolerance must therefore be clarified by a doctor to determine whether the symptoms are related to food intolerance or whether there is another possible cause.

In addition to the physical complaints, other restrictions are possible. One phenomenon that probably often affects you is the fatigue that can occur with lactose intolerance.

But this also means that milk itself has a reputation for making you tired. Warm milk with honey has been used as a sleep aid for generations. Why cow's milk or lactose intolerance makes you particularly tired depends on the special ingredients in the milk and other factors .

Milk contains the protein tryptophan . The messenger substance melatonin develops from this substance. Melatonin is responsible for the sleep-wake rhythm. Melatonin is now also available as a spray or in tablet form as a sleep aid. Dairy products such as quark also contain tryptophan, which can make you tired.

Another cause of fatigue is the stress on the body caused by the intolerance.

When the organism struggles with the effects of lactose, also known as milk sugar, tiredness and exhaustion are no wonder. In addition to increased tiredness, other symptoms can occur.

Affected people report :

  • difficulty concentrating,
  • lack of motivation,
  • memory disorders,
  • depressive moods,
  • sweats or
  • Sleep disorders.


These symptoms are not typical, but are still common. If lactose intolerance is responsible for the tiredness , this can be quickly remedied by switching to an alternative to cow's milk.

If you decide to replace conventional milk , you have a wide range of plant-based milk alternatives available. This also solves the problem that milk makes you tired. Because oat milk or an alternative to cow's milk doesn't make you tired because it lacks tryptophan.

What exactly is lactose intolerance?

Lactose intolerance is a food intolerance . Lactose is milk sugar present in cow's milk. Lactose is also contained in sheep's milk and goat's milk.

Lactose is also found in dairy products, for example :

  • Quark
  • yogurt
  • cream
  • whey
  • Fresh and soft cheese


Butter is lactose-free. In cheese, the lactose content depends on the ripeness of the cheese. The longer a cheese matures, the lower the lactose content. As a result of fermentation and maturation, the lactose content of semi-hard and hard cheese continually decreases.

Because milk and dairy products could also be used in other foods during the processing process, it makes sense to take a look at the small print on the packaging. If you want to avoid lactose as much as possible, almost all finished products, semi-processed or fully processed foods should be viewed critically.

These include, among other things, bread and baked goods as well as baking mixes . The addition of lactose must be stated on the packaging. Bakeries and catering establishments must include lactose in the allergen list.

Caution : Lactose is also used as a carrier for medicines, sweetener tablets and flavors. Even tiny amounts can be found in spice mixtures. These additives are harmless in tiny amounts.

However, if lactose intolerance is very severe , you should avoid such products. According to the Allergen Labeling Ordinance, manufacturers are obliged to declare milk, lactose, whey and whey powder.

Lebensmittel ohne Laktose verwenden

This is how a diet without lactose works

Avoiding lactose is quite easy . Apart from milk and milk products, the substance is not found in any other food - provided that the food is unprocessed.

Lactose only gets into the products during further processing .

If you use fresh and unprocessed foods , you can easily get tired of intolerance and all other complaints under control.

Cooking yourself is the best way to stay healthy!

What does lactose do in the body?

In order to understand what lactose and the associated intolerance are and can trigger in the body, let's take a short excursion into chemistry and medicine.

Lactose or milk sugar is a so-called disaccharide .

In order for the intestine to absorb and process the lactose , it must be broken down into the two components galactose and glucose. This is the only way the disaccharide can pass through the intestinal wall of the small intestine. The enzyme lactase is required for this breakdown.

When lactose intolerance occurs, there is an enzyme deficiency in the body. The enzyme lactase is produced in the small intestine, although not by all people. If you suffer from lactose intolerance, your body cannot produce lactase - or at least not as much as the organism would need to break it down.

The lactose therefore continues to migrate unchanged into the large intestine. There it is food for certain bacteria. During this process, waste products are formed, including gases such as hydrogen, carbon dioxide and methane gases, short-chain fatty acids and lactic acids. The waste materials are the cause of numerous complaints .

The gases are the main trigger that creates unpleasant pressure in the upper abdomen . These gases are also responsible for abdominal pain and bloating . The waste products that are produced in the large intestine cause diarrhea.

The milk and fatty acids as waste products are water-absorbing, so that more fluid enters the intestines and diarrhea occurs as a result, often very suddenly.

Milk can cause constipation if it produces methane gas. This gas leads to slowed intestinal activity, which in turn is the cause of intestinal sluggishness and constipation.

Lactose intolerance: Why do some people develop intolerance?

The negative reactions to lactose are genetically determined. Either the consequences become apparent from birth, or the organism develops lactose intolerance in later years of life, often only in adulthood. What is interesting in this context is the worldwide distribution.

In Northern Europe the phenomenon is rather rare, while in Asia and Africa people have very poor tolerance to lactose. The ability to produce the enzyme lactase in the small intestine is almost completely absent in the inhabitants of the continents of Africa and Asia. In America, around 50 percent of the population is affected by lactose intolerance .

The reason for this seems to lie in the development of eating habits : While the keeping of cows in food production has become more and more widespread in Europe, especially in Northern Europe, in the last few centuries, cow's milk was and is not a common food in Asia and Africa.


Lactose intolerance is therefore not necessarily considered a disease, but rather is a consequence of adaptation to the foods available to a population group.

There is also lactose intolerance , which only develops later in life. Either the body's own lactase production decreases, which is the case for many Northern Europeans, or there is another underlying disease.

The technical term for this is acquired, secondary lactose intolerance, as opposed to the primary form, which is either present from birth or develops with age. The secondary form is a result of another disease that damages the intestinal lining and thus reduces the production of lactase .

These diseases come into question :

  • gastrointestinal infections,
  • chronic inflammatory bowel diseases, for example Crohn's disease,
  • Food allergies or even
  • Gluten intolerance (celiac disease).


Operations in the gastrointestinal area can also be a trigger. Secondary lactose intolerance does not have to be permanent.

It can disappear again when the original disease is cured. The chances are very good that if you are lactose intolerant, the fatigue will gradually decrease.

Introspection and visiting a doctor

You can easily find out whether you really suffer from lactose intolerance by observing yourself . A food diary in which you record all the foods you eat and the symptoms that arise as a result is a good guide. Your doctor may do additional tests to be sure.

Lactose intolerance and the tiredness that often comes with it are not fate - the intolerance cannot be cured directly, but with a change in diet you will be fine again.

As an immediate aid, but also for holidays with meals in a hotel, for visits to restaurants or similar occasions, there are lactase tablets available in the pharmacy that compensate for the lack of the body's own lactase .

Have lactose intolerance checked by your doctor

Lactose intolerance can vary in severity

Lactase deficiency can vary from person to person . Some people no longer produce lactase at all and therefore react strongly to even the smallest amounts of lactose in their food.

If the degree of lactase deficiency is higher, a certain amount of enzymes is still formed. Then small amounts of lactose can be tolerated relatively well.

Symptoms become more pronounced when the lactose content in the diet is high . The composition of the food also plays a role. Yogurt or kefir contain a lot of lactose, but also a large amount of lactic acid bacteria. These bacteria can break down large amounts of lactose that would otherwise put a strain on the intestines.

Babies and lactose: Is a baby allergic to cow's milk?

Regardless of the habitat, there is one major exception : babies generally have no difficulty tolerating milk sugar. That's a good thing, because lactose is present in breast milk.

Even newborns can generally produce the enzyme lactase so that breastfeeding works without any problems. If the mother is not breastfeeding, a diet with dairy products made from cow's milk is possible.

After weaning or after the end of the phase in which a baby is provided with special baby food , lactase production gradually decreases. A natural lactase deficiency occurs. The decline occurs between the ages of 5 and 20. Whether the body can still tolerate lactose depends very much on the individual.

Many people tolerate milk and dairy products well throughout their lives , but others develop more or less severe symptoms. Intolerance is particularly concerning because the symptoms are very annoying and unpleasant.

Cow's milk and products made from it are not essential for life . Cow's milk contains many components that are considered healthy. But animal fats and animal protein can easily be replaced with plant-based products.

In rare cases, a baby may have a congenital allergy to cow's milk . This is a genetic defect that is responsible for the lack of lactase production.

With this absolute lactose intolerance, affected babies get persistent diarrhea after breastfeeding, but also when fed with industrially produced milk powder based on cow's milk.

In order to prevent serious illnesses, it is necessary to avoid lactose for life. There are lactose-free milk powders available for baby nutrition so that the infant can grow and thrive without restrictions.

Attention : The pediatrician can use tests to determine whether it is actually congenital lactose intolerance. Sometimes newborns have problems producing lactase on their own in the first few weeks of life, but the difficulties quickly disappear.

Lactose intolerance in children, adolescents and adults

If you notice certain symptoms in your child (or even in young children) or yourself after eating, it is worth taking a look at the individual foods.

Since lactose intolerance can develop in many different ways , milk is not always the trigger. Gluten intolerance is often the case, especially when there are problems with digestion, stomach pain and diarrhea. That's why it's important to find out the exact culprit.

The main difference between lactose and gluten intolerance is this : lactose intolerance is unpleasant, but not threatening to the organism in a direct sense.

However, if diarrhea occurs frequently after eating, the body cannot properly utilize other food components because the food passes through the intestines too quickly.

That's why it makes a lot of sense to avoid lactose , not only to prevent the symptoms, but also to ensure that the body gets all the nutrients it needs with the right foods.

If, on the other hand, there is gluten or wheat intolerance or even celiac disease, serious intestinal diseases can occur.

In this case , gluten must be avoided in any form : you should replace bread, cakes and grain products such as pasta with gluten-free foods to stay healthy.

Gluten is also found in other foods, often only in small amounts. But even small amounts can be enough to trigger the typical symptoms.

Eat well and healthily despite lactose intolerance

The vegan diet is an ideal diet for anyone affected by lactose intolerance. Vegans look closely at the ingredients in food.

Since lactose can only be present in products of animal origin, you are automatically on the safe side with a vegan diet.

But people who are so-called omnivores or vegetarians can also switch to many products without lactose so that eating becomes a pleasure without regret.

It's worth switching to foods that at first glance don't contain any lactose at all, as are milk substitutes , yoghurt or cream. At Greenforce you will find an extensive selection - just take a look at the range and discover delicious alternatives!

Replace milk

The range of vegan plant milk is very large. Milk made from oats is now a classic, but there are also good cow's milk alternatives based on soy, almonds, hazelnuts, cashews or rice. Healthy nutrients and less cholesterol than in cow's milk are convincing advantages.

In addition, plant-based milk offers the same variety of uses as cow's milk. You can enjoy them on their own, use them for muesli or for frothing or use them for baking. The organic oat drink from Greenforce is particularly practical and comes to you as a powder that you can mix yourself - space-saving and delicious!

If you love buttermilk and need to watch out for lactose, you have two options. Either you buy a vegan buttermilk substitute or you simply make the buttermilk yourself.

For this you need soy milk and an acidulant, preferably apple cider vinegar or lemon juice. Start by using just a small amount of vinegar or juice and taste the results.

So that the acid can develop well, let the buttermilk rest for about a quarter of an hour. The delicately sour taste gives your own creation a special freshness. Variants with fruit are also possible : pureed strawberries or apricots make delicious fruit buttermilk, without any lactose.

Since replacing milk can be very easy, you are probably also interested in a good yogurt alternative . You can get a variety of vegan yoghurts in stores. At Greenforce, the alternative product is called Vegurt . Similar to the oat drink, you can mix the Vegurt with water yourself in no time.

Vegan cream should not be missing in the kitchen. The basis is oats, almonds, soy, spelled or coconut. There are differences in taste, so it's best to just try them out . Your favorite style is most likely there.

The intended use is also important. Pay attention to whether the cream should be suitable for cooking or whipping.

You can also get vegan products not only when it comes to milk and yoghurt alternatives . Even with meat and sausage substitutes, it is guaranteed that there is no lactose in the substitute products.

This saves you the trouble of studying the list of ingredients if you know that you can enjoy it without any problems, without unpleasant pressure in your upper abdomen or other discomfort.

No more tiredness due to lactose intolerance!

Tired after eating, that was once - now you know where the tiredness comes from and what you can do about it. If your baby has a cow's milk allergy, your children or your partner are struggling with gastrointestinal problems and fatigue, a diet without dairy products finally offers relief.

The taste experiences and variety of milk, yoghurt, buttermilk and cream are retained!

And don't forget : Cooking and eating vegan means you are actively choosing to protect animals and our environment. Vegan foods are created without factory farming and without inhumane conditions.

This is more than just a nice side effect! The vast majority of vegan products are available in organic quality. You don't have to go without anything, because alternative foods provide the body with all the nutrients despite lactose intolerance, sometimes even healthier than cow's milk products !