What is histamine intolerance?

Published 28 May 2023 • By Candice Salomé

Histamine intolerance syndrome (or histaminosis) is a set of chronic symptoms caused by an imbalance between the body's histamine accumulation and its degradation capacity, resulting in excessive levels of histamine. 

So what exactly is histamine? What are the symptoms of histamine intolerance? How can histamine intolerance be diagnosed? What are the possible treatments?

We explain it all in our article!

What is histamine intolerance?

What is histamine? 

Histamine is a biological molecule naturally synthesised in humans and animals. It is a so-called "messenger substance" that transmits and disseminates information between cells and plays an important physiological role in several body functions. Histamine is synthesised from histidine (an amino acid) and stored mainly in immune cells, mast cells and basophilic cells. In our body, it is mainly degraded by the enzyme diamine oxidase (DAO).

Histamine plays a role in the digestive system by stimulating the secretion of acidity necessary for digestion and sterilisation of food. At the neurological level, it is involved in wakefulness and sleep.

Histamine exerts its effects via the activation of four histamine receptors: H1, H2, H3 and H4. 

H1 receptors can be found in almost the entire human body, H2 receptors are present in the stomach, H3 receptors in the lungs, intestine and the brain, and finally H4 receptors are located mainly in the brain. Histamine therefore acts on different organs (the brain, stomach, cardiovascular and respiratory systems, etc.), which may explain the diversity of signs when too much histamine is released.

What symptoms are caused by histamine intolerance? 

In case of an allergy, histamine is released en masse when the body is in contact with a substance to which it is sensitive. This causes the dilation of the small blood vessels (called capillaries) which in its turn leads to redness of the skin, and increases the release of water from the vessels, leading to oedema, lowered blood pressure, increased heart rate and constriction of the bronchi.

In fact, due to a deficiency, dysfunction or altered activity of the enzyme diamine oxidase (DAO), some people cannot tolerate histamine. It has been estimated that 1% of the population is histamine intolerant.

The clinical picture of histamine intolerance includes many symptoms:

  • Sudden redness of the face,
  • Itching and redness on the body skin,
  • Digestive disorders such as nausea, vomiting, diarrhoea, abdominal pain,
  • Drop in blood pressure, dizziness, tachycardia,
  • Runny nose, chronic cold,
  • Headache, migraine,
  • Red eyes, swelling of the lips,
  • In women: menstrual disorders.

These symptoms do not manifest themselves in the same way in everyone. Some people develop only some of the symptoms listed above.

The main trigger for such disorders is a high intake of histamine through the person's diet. In some people, the body can no longer sufficiently break down histamine that comes from food when there is not enough DAO.

Histamine is found in large quantities in both animal and plant products. The fermentation process influences the histamine content of food. The fresher the food, the better it is generally tolerated. 

Foods such as fermented cheeses, cold cuts, fish - especially when dried or smoked - fruit (especially strawberries), vegetables (tomatoes, spinach), sauerkraut, chocolate, beer, wine, etc. are rich in histamine

Moreover, histamine secretion is increased if a person is stressed. Prolonged stress can lead to a constant increase in histamine secretion.

Drugs or alcohol, even in small amounts, can temporarily block the activity of the enzyme diamine oxidase (DAO). It can also be impaired as a result of chronic inflammatory bowel disease (IBD) such as Crohn's disease or coeliac disease. In the case of chronic disease, the enzyme deficiency is permanent.

How do you know if you are intolerant to histamine? 

Histamine intolerance is different from histamine allergy. However, it is often difficult to distinguish between the two conditions since the symptoms appear after eating certain foods and are almost identical.

Since the symptoms are not specific, certain food allergies and intolerances such as lactose intolerance, coeliac disease or fructose malabsorption, or other disorders with similar symptoms, should be excluded in the first place.

Usually, the doctor will test for food intolerances and allergies. However, these tests do not detect histamine intolerance.

The diagnosis of histamine intolerance
is initially clinical, through questioning. It is also possible to measure the activity of the enzyme diamine oxidase (DAO), which becomes disturbed in the case of histamine intolerance.

If histamine intolerance is suspected, a low-histamine diet can be prescribed for 10 to 14 days and should be supervised by a dietician or a nutritionist. Histamine intolerance is confirmed if the symptoms tend to improve during this period.

How can histamine intolerance be treated? 


Once histamine intolerance has been diagnosed, the most effective treatment is to avoid histamine-rich foods. However, this can be complicated as histamine is present in many foods and manufacturers are not obliged to indicate this on the packaging.

Many food lists are available on the Internet but few contain scientific measurement data on the histamine content. This is because the histamine content is influenced by several factors, such as the amount of food consumed and the individual tolerance level. 

Foods that have undergone a fermentation or ripening process should generally be avoided:


Source: nutritionbyerin.com


In order to limit the symptoms that occur after a significant release of histamine, antihistamine drugs can be used. 

Histamine acts on cell receptors called H1 receptors. Anti-H1 antihistamines will take the place of histamine on these receptors and prevent its activation. 

There are two categories of antihistamines:

  • First-generation anti-H1 drugs: they have many side effects such as drowsiness and fatigue,
  • Second-generation anti-H1 drugs have few or no side effects.

Histamine intolerance cannot be cured by medication. However, antihistamine drugs can help relieve symptoms in the short term.

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Take care!

avatar Candice Salomé

Author: Candice Salomé, Health Writer

Candice is a content creator at Carenity and specialises in writing health articles. She has a particular interest in the fields of women's health, well-being and sport. 

Candice holds a master's degree in... >> Learn more

Who reviewed it: Laury Sellem, Doctor of Nutrition

Laury holds a PhD in Nutrition Sciences (University of Reading, UK) and a master's in Nutrition and Human Health (AgroParisTech, France). She has conducted clinical and epidemiological research projects in Nutrition... >> Learn more


lesmal • Ambassador
on 31/05/2023

Thank you for explaining more about histamines.

I'm from a very allergic prone family, and no matter what I eat it seems to cause a reaction. I have to monitor it regularly, and take an antihistamine medication daily (Ceterizine) for this purpose.

on 03/06/2023

Thank you for an excellent article which goes some way to making sense of my health situation. I have currently got my U.C. under control ( with the help of Prednisalone and an excellent G.P.) after quite a traumatic episode.

Now I need to work out a diet that I can accept given that a lot of my favourite foods are on the no-no list.

I too have been taking daily Ceterizine to counteract my body's reaction to Preds.

I have an appointment with Gastro consultant 12th June for a chin wag which could be interesting. We have different opinions on the causes of my occasional ailments.

Pippadog • Ambassador
on 05/06/2023

Thanks for the contact, no I do not suffer with heart failure.

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