Often involved in allergic symptoms and sometimes poorly tolerated when supplied by food, histamine is nevertheless an essential molecule for the body.

What is histamine?

Histamine is a biogenic amine produced by our own cells from an amino acid called histidine.

It is a mediator that acts as a relay between different cells and systems and is essential for the proper functioning of our body.

It is stored by our immune cells, which explains why it is involved in allergic reactions.

Histamine is also found in many foods, and some people cannot tolerate large amounts of it.

Excess histamine is broken down by an enzyme called diamine oxidase (DAO).

What is its function in the organism?

Histamine is a messenger that transmits stimuli to ensure the proper functioning of the immune, nervous and bone systems.

It is essential for our bodies, but in small doses.

Without it, we would not be able to fight off microbes, we would not be able to regulate stomach acid properly and therefore we would not be able to digest properly.

It also allows us to stay awake.

But in too high a dose, either through overproduction by our bodies or through excessive ingestion, it can be harmful.

Intolerance to histamine

Some people have difficulty tolerating the histamine in food and develop intolerance reactions very similar to traditional allergic reactions.

What causes this intolerance?

It seems that some people are unable to break down all the histamine they ingest, either because they have a deficiency of OAD or because they have a chronic bowel condition that causes a build-up of histamine in the body.

This histamine overflow causes characteristic symptoms very similar to allergic symptoms.

The histamine released by the cells causes a reaction: in the veins (vasodilation), in the bronchi (bronchoconstriction), in the skin (itching and oedema), in the heart (tachycardia), in the nervous system (system maintenance).

In practice, therefore, it is very difficult to tell the difference between a histamine intolerance and a food allergy to a food containing histamine, such as shellfish.

How is histamine intolerance diagnosed?

If you suspect you have histamine intolerance, you should see your allergist, who will ask you about your diet and offer allergy skin tests to rule out a possible food allergy.

This consultation will usually allow you to make a diagnosis.

In the case of food intolerance, there is a concept of dose dependency: the higher the dose ingested, the stronger the reaction.

If a reaction occurs after a significant intake of a histamine-rich food, and if allergy tests are negative, we can conclude that there is an intolerance.

Caution: While allergies can be diagnosed using reliable skin or blood tests recognised by health authorities, food intolerances cannot. There are tests for histamine intolerance, but they are very controversial and not scientifically validated.

It is important to remember that these tests, which are not reimbursed, are useless, and in fact make patients' care worse and their journey more difficult. This is also the case with all IgG4 tests for food intolerance.

Which foods contain the most histamine?

The foods that contain the most histamine are those that are produced by fermentation or ripening.

These include all foods that contain: alcohol, bacteria, yeast or vinegar.

Among the most histamine-rich foods are:

• Cured meats (sausages, bacon, salami, Bündnerfleisch, raw, cooked or smoked ham and sliced cured meats in general)
• Certain fish (mackerel, tuna, sardines, anchovies, etc., especially when smoked, marinated, salted or dried and canned)
• Fermented cheeses (Emmental, Parmesan, Roquefort, Camembert, etc.)
• Sauerkraut, tomatoes (and their derivatives: tomato juice, tomato sauce, ketchup, spinach, lentils, olives, avocados, aubergines and mushrooms)
• Alcohol (especially wine and beer)
• Chocolate

How to replace them?

In order to limit your histamine intake, it is necessary to reduce as much as possible foods that have been treated by salting, drying or fermentation, and to favour fresh foods.

We will give priority to:

• Fresh meat and poultry
• Fresh or frozen fish, preferably white fish: cod, coalfish, hake, etc.
• Fresh dairy products (very fresh and low salt cheese, white cheese, yoghurt, etc.)
• All vegetables (except those mentioned above)