Histamine Intolerance - Symptoms of Food Intolerance & the Many Faces of Histamine Intolerance

Histamine is primarily a biogenic amine formed from the amino acid histidine. It is found in human, animal, and plant organisms. This neurotransmitter plays an important role and is essential for our immune system. 

Mast cells are the primary stores of histamine. It is known as a defense substance against harmful substances. Anyone who has ever come into contact with the stinging hairs of a stinging nettle knows just how powerful histamine’s defensive potential is. The affected area of skin turns red, itches, hurts, and swells.

In some people, however, the body is unable to break down histamine quickly enough.

When histamine enters the body through food, it causes inflammation, which can lead to the following symptoms:

• Nausea
• Diarrhea
• Itchy eyes
• Headaches

Doctors refer to this as histamine intolerance. The clinical presentation of histamine intolerance varies widely and can range from mild to significantly debilitating symptoms.

Histamine intolerance occurs when the body cannot break down enough histamine in the intestines. As a result, histamine levels in the blood rise. This is usually due to low levels of the enzyme diamine oxidase (DAO). This enzyme is responsible for breaking down digested histamine.

Histamine sensitivity is relatively rare. It affects approximately 800,000 people in Germany.

Foods with high histamine content include:

• aged cheese
• yogurt
• kefir
• sauerkraut
• legumes
• Chocolate
• Nuts
• Tomatoes
• Meat products
• Pickled foods
• Smoked meat
• Vinegar
• Alcoholic beverages (especially wine, champagne, and beer)

Foods with high histamine content @ Brigitte Bonaposta /AdobeStock

It is often difficult for a doctor to diagnose histamine intolerance. This is because the symptoms are very diverse and overlap with typical symptoms of other conditions. Symptoms similar to those of allergies or other food intolerances also frequently occur, which makes it even more difficult to distinguish between them.

The symptoms can affect the lungs, skin, and brain, for example, though gastrointestinal symptoms are the most common.

People with histamine intolerance often suffer from the following symptoms:

• Diarrhea
• Headaches
• Bloating
• Abdominal pain
• Nausea
• Skin rashes, especially on the head and chest
• a stuffy, runny, or itchy nose
• Red, itchy, or watery eyes
• Dizziness
• Heart palpitations

These symptoms of histamine intolerance can vary greatly in severity from person to person and depend on the amount of histamine ingested.

Skin redness associated with histamine intolerance @ sarenac77 /AdobeStock

Histamine intolerance means that the body has difficulty breaking down histamine.

Normally, DAO and, to a lesser extent, an enzyme called histamine N-methyltransferase (HNMT) break down ingested histamine. However, several factors can impair the functioning of DAO and HNMT. Other possible causes include genetic factors, intestinal disorders, or an imbalance in the gut microbiota.

If the body cannot break down histamine from food, it passes through the intestinal mucosa and enters the bloodstream. This can trigger an immune response. In such cases, there is an intolerance to orally ingested histamine because the body cannot break it down sufficiently.

Many prescription medications can affect DAO and HNMT levels in the body. 

Some examples of medications include:

• pain relievers
• diuretics
• certain expectorants
• Medications for heartburn
• Certain antibiotics

In addition, heavy alcohol consumption and chronic gastrointestinal disorders can contribute to the development of histamine sensitivity.

Currently, there are no established tests for diagnosing histamine sensitivity. It is possible to measure DAO activity and histamine levels in the blood. Typical blood allergy tests or skin tests do not detect histamine intolerance, as it is not an allergy.

As with all health issues, you should first consult your primary care physician if you suspect you have histamine intolerance. A strong suspicion of histamine intolerance often arises from a combination of typical symptoms and a temporal association with certain foods. However, histamine intolerance can generally only be diagnosed through an elimination diet. 

During this diet, you avoid all trigger foods for a specific period of time. Afterward, you gradually reintroduce them to see how your body reacts.

People often consult their primary care physician if they suspect they have histamine intolerance. Depending on the symptoms, they may then be referred to the following specialists:

• Internal Medicine
• Gastroenterology
• Nutritional Medicine or 
• Allergists specializing in food intolerances

The most important step in treating histamine intolerance is reducing histamine intake. This can be achieved through a low-histamine diet. Doctors also recommend keeping a symptom or food diary. This allows you to document when symptoms occur and whether a change in diet reduces the frequency of symptoms.

The goal of a low-histamine diet should not be simply to create a list of forbidden foods. Rather, you should determine how much histamine in which foods you can tolerate (your individual tolerance limit). 

In addition, you should pay attention to the composition of the foods and the intervals between meals. It has been shown that simply eliminating histamine-rich foods from your diet is not enough. Rather, a proper diet—one that is low in starch and sugar while being plant-based and rich in protein and fat—has a more beneficial effect on symptoms of histamine intolerance. The histamine content of foods alone is not a very reliable indicator of tolerability. 

In addition, antihistamines may be used in certain cases to relieve acute symptoms.

There is hope for those affected by histamine intolerance, as research shows that a multi-pronged approach to managing symptoms is promising. People with histamine intolerance benefit particularly from making early adjustments to their diet and lifestyle.

This includes:

• identifying trigger foods
• following a low-histamine diet
• managing stress levels through yoga or meditation
• taking certain vitamins and minerals, and
• taking a histamine-friendly probiotic

The course of the condition depends on how quickly you identify and eliminate the triggering factors. For example, if certain medications exacerbate the symptoms, simply switching to a different medication may be enough to alleviate the symptoms.

1. What happens in the body when someone has histamine intolerance?
In cases of histamine intolerance, the body has difficulty processing histamine ingested orally, causing histamine to accumulate in the body and potentially trigger symptoms.

2. Which foods can trigger symptoms?
Foods containing histamine, as well as certain biogenic amines or so-called histamine liberators, can exacerbate symptoms.

3. Is histamine intolerance an allergy?
No, histamine intolerance is not an allergy, but rather an intolerance to a neurotransmitter in which enzymes such as diamine oxidase do not function properly.

4. What should you do if you suspect histamine intolerance?
The recommended approach when intolerance is suspected usually involves an elimination diet followed by the gradual reintroduction of individual foods. A possible histamine intolerance should always be medically evaluated.