Histamine intolerance - symptoms, causes, therapies

Histamine intolerance is a metabolic or breakdown disorder of histamine, a biogenic amine that occurs naturally in animal and plant cells but is also ingested through food. It is involved in many (metabolic) processes in the body.

These include appetite, sleep-wake cycle, learning ability, concentration and memory – and even our emotions. Histamine also acts as a tissue hormone and neurotransmitter. It stimulates gastric juice secretion and has a vasodilatory effect, but histamine also plays a central role in inflammation in the body as a mediator in allergic reactions, bronchial asthma, hay fever, and hives.

Histamine breakdown, histamine levels and histamine barrel

The enzymes responsible for breaking down histamine are primarily diamine oxidase (DAO) in the small intestine and histamine N-methyltransferase (HNMT), which is located in the liver, bronchial mucosa, and central nervous system (CNS). Both can be disrupted by various factors. For example, consuming histamine-rich foods or the release of excessive histamine from mast cells can lead to elevated histamine levels in the blood. This condition is also known as histaminosis.

Unlike an allergy, symptoms only arise when a certain level of histamine in the body is exceeded. We call this the "histamine barrel," which then overflows. This imbalance or dysregulation of histamine breakdown can lead to a variety of ailments in the body, because when there is a histamine surplus, an increased amount of histamine enters the bloodstream and is distributed throughout the body.

Symptoms of histamine intolerance – from nausea and migraines to depression, many symptoms are possible.

We all ingest histamine through food, and each of us also produces histamine in our own mast cells – and that's a good thing. Histamine is involved in many important metabolic and regulatory processes, such as our sleep-wake cycle. It also influences our appetite, emotions, memory, and learning ability, and regulates part of our hormonal balance.

However, if our histamine metabolism is disrupted and we have too much histamine in the body, a wide variety of symptoms can occur that can impair our well-being on a physical and mental level.

Learn about the symptoms of histamine intolerance and how to best manage them in our detailed article on histamine intolerance symptoms. Happy reading!

Histamine symptoms can vary greatly in type and intensity: possible symptoms of histamine intolerance

Gastrointestinal tract:
Nausea, stomach cramps, bloating, constipation, diarrhea, intestinal cramps

Skin:
Itching, hives, urticaria, swelling, skin redness, extreme reactions to insect bites, acne, skin blemishes, rash

Autonomic nervous system:
Difficulty concentrating, memory problems, brain fog, drowsiness, exhaustion, insomnia, loss of appetite or constant appetite, tingling in the limbs, headaches, inner restlessness

Cardiovascular system:
Low blood pressure, dizziness, sweating, nausea, rapid heartbeat, heart rhythm disturbances

Respiratory system:
Sore throat, runny nose, blocked nose, cough, increased mucus production, feverish feeling

Psyche:
Depression, depressive moods, winter depression, mood swings, states of exhaustion

More:
Increased PMS symptoms, recurrent cystitis, muscle tension, heightened sensitivity.

Sources:
Dirk Schweigler: Histamine intolerance from a completely new perspective
Swiss Interest Group for Histamine Intolerance (SIGHI)
Nutrition & Medicine: Nutritional therapy for histamine intolerance

Diagnosis of histamine intolerance – why a change in diet is the best way to make the diagnosis

Diagnosing histamine intolerance isn't easy, as there's currently no reliable medical test for it, since no single test result is 100% conclusive. The simplest approach is to switch to a low-histamine diet.

But why is that?
There are various methods for measuring the concentration or activity of histamine or the histamine-degrading enzyme diamine oxidase (DAO) in the body. However, determining the concentration of the enzyme diamine oxidase (DAO) in the blood is the most common method used to diagnose histamine intolerance. The reliability of this test is rather limited, as the production of the enzyme can fluctuate considerably over time due to external influences.

The DAO level in the blood actually provides little information about whether too little DAO is being produced in the gut. Another testing option is measuring histamine in stool, but this doesn't allow for a definitive diagnosis; rather, it only indicates whether histamine intolerance is likely or unlikely.

The elimination diet
To be absolutely sure whether you suffer from a histamine intolerance, the elimination diet is the best approach. For this, you eliminate histamine-rich foods for approximately 4-12 weeks and observe your symptoms. Keeping a food and symptom diary is also recommended.

Based on the symptoms, a therapist can then identify the foods that trigger the discomfort.

Histamine-free diet – unfortunately, there is no such thing as a histamine-free diet.

A completely histamine-free diet is virtually impossible, as almost every food contains small amounts of histamine. It's important to avoid "histamine bombs" such as alcohol, tomatoes, chocolate, sauerkraut, aged cheese, and smoked ham. You can find a list of low-histamine foods here . If your symptoms improve during this period, it's very likely you have a histamine intolerance. If your suspicion of a histamine intolerance is confirmed, it's important to make long-term dietary changes and identify or address the underlying causes.

What should you do if your symptoms don't improve despite an elimination diet?
If your symptoms show little to no improvement on a strict low-histamine diet, there is likely another underlying cause. In this case, further medical tests are recommended. Consult your general practitioner, internist, naturopathic practitioner, or allergist to investigate other potential triggers for your symptoms.

Diseases with similar symptoms can include, for example:

• Mast cell activation syndrome (MCAS)
• other food intolerances (gluten, lactose, fructose, sorbitol, salicylate, lactate, oxalate)
• Food allergies or cross-allergies
• SIBO (small intestinal bacterial overgrowth)
• Helicobacter pylori and E. coli
• Leaky Gut Syndrom
• HPU / KPU (metabolic disorder)

In conclusion, if the following points apply, a histamine intolerance is relatively certain:

• You have at least two symptoms that are typical of histamine intolerance.
• The symptoms generally improve with a strict low-histamine diet.
• Acute symptoms subside after taking antihistamines.

To get an initial assessment of whether you might be affected by histamine intolerance, we recommend our free 2-minute histamine test. Important: This test does not replace a medical diagnosis.

Causes of histamine intolerance – and what your hormones, gut, or liver might have to do with it.

The causes of histamine intolerance can be just as varied and extensive as its symptoms. For this reason, diagnosing histamine intolerance – and identifying the underlying causes – is often a real challenge for both doctors and sufferers.

These are possible causes of histamine intolerance:

1. Disrupted intestinal metabolism

• Leaky Gut
• Dysbiosis
• SIBO
• Candida
• Gastrointestinal infection

2. Impaired liver metabolism

• Heavy metal contamination
• sluggish liver
• fatty liver

3. Hormonal imbalance

• Estrogen dominance
• Puberty, pregnancy, menopause

4. Disrupted thyroid metabolism

• Hashimoto

5. Other causes

• Nutrient deficiency (e.g., vitamin B6)
• Taking medication (e.g., antibiotics)
• Bacteria, such as Helicobacter pylori or E. coli
• unbalanced diet
• Unstable cervical spine or TMJ
• stress

Therapy for histamine intolerance – why a low-histamine diet is the basis for greater well-being

Perhaps after your diagnosis, your doctor sent you home with the statement, "Histamine intolerance is incurable; you'll have to learn to live with it." Even back then, we couldn't accept this statement and began to research it.

Today, thanks to our studies, training, and experience, we can offer you hope. You can do something about your histamine intolerance and become more symptom-free with certain tools. Furthermore, histamine intolerance even has the potential to be cured, but this always depends on the underlying cause(s)!

Possible causes and therapies
The most common cause of histamine intolerance lies in our metabolism, primarily affecting the intestines, liver, and thyroid gland. Furthermore, medications, stress, and high levels of mental and physical strain significantly impact our histamine levels, as well as our digestion and metabolism. Therefore, it is crucial to address histamine intolerance holistically, considering and treating it on multiple levels.

In addition to conventional "therapy" using antihistamines and a low-histamine diet, we have developed a holistic approach that allows you to tackle the root causes and become sustainably symptom-free.

You no longer have to accept your current condition, but can actively work on your health and experience improvement!

Learn more about the next steps now!

These three steps are essential to becoming symptom-free again despite your histamine intolerance.

Histamine intolerance is an acquired (or sometimes congenital) non-immunological metabolic disorder, which in the vast majority of cases has one or more underlying causes. We therefore encourage you to address your histamine intolerance holistically and naturally.

Because we – just like you – were also at the point where we no longer wanted to accept our diagnosis and symptoms as a permanent condition. So we spent years researching, studying, and gaining experience – and found a way to become more symptom-free – and even to be able to eat histamine-rich foods again without problems.

You can take the following steps to achieve this:

1. Change in diet

2. Finding the cause

3. Natural metabolic relief

Learn now how you can achieve greater freedom from discomfort in just a few steps – and take control of your health again.

1. Change in diet

Changing your diet to a low-histamine and anti-inflammatory diet is the first step towards greater freedom from symptoms and essential for alleviating them. The following food groups should be avoided:

• Foods high in histamine (e.g., ham, red wine, or Parmesan cheese)
• Histamine liberators (e.g. citrus fruits or cocoa)
• Foods containing competing biogenic amines (e.g., bananas)
• DAO inhibitors (e.g., alcohol)

At the beginning of the dietary change, an elimination phase of 4-12 weeks should be observed to keep histamine levels low in the long term. During this phase, all food groups that are either high in histamine, considered histamine liberators, contain other biogenic amines, or can inhibit DAO should be avoided. You can end the elimination phase when you have been symptom-free for at least one week. It is also not unhealthy for the body if the elimination phase lasts longer than 12 weeks.

After this phase, you can gradually introduce new foods to see which ones you tolerate. You can find a food list here .

Please note that this food list is only a general guide and may not apply to everyone. Food tolerance in people with histamine intolerance varies greatly from person to person. To find out which foods you tolerate well and which you don't, you can keep a food and symptom diary.

2. Finding the cause

Histamine intolerance can have various causes. If the histamine intolerance is not genetic (an enzyme deficiency from birth), it is acquired and can improve or even disappear with targeted therapy addressing the underlying causes.

To find the cause, it is first important to know where histamine breakdown mainly takes place in the body.
There are two main enzymes that break down histamine into an inactive histamine breakdown product:

• Diamine oxidase (DAO): is located, among other places, extracellularly (unprotected outside the cell) in the intestine.
• Histamine N-methyltransferase (HNMT): is located, among other places, intracellularly (protected within the cell), including in the liver.

Since DAO is particularly susceptible to external influences, the first possible cause lies in the gut. The following disorders and diseases can reduce DAO activity or histamine breakdown, and you can have these tested for by a gastroenterologist, internist, or naturopathic practitioner:

• Gastrointestinal infection
• Leaky gut (increased intestinal permeability)
• Intestinal flora dysbiosis (imbalance of intestinal bacteria)
• SIBO/IMO (small intestinal bacterial overgrowth)
• Candidiasis (yeast infection)
• Viral infections (e.g. Covid-19 or Epstein-Barr virus)
• Bacterial infections (e.g. Helicobacter pylori or E. coli)

Furthermore, the activity of HNTM can be limited by certain factors:

• Liver overload
• Heavy metal contamination
• fatty liver

One reason why women are particularly affected by histamine intolerance is hormones. You can have a hormonal imbalance tested by a gynecologist or endocrinologist. In this context, a histamine metabolism disorder can develop in the following phases:

• puberty
• pregnancy
• menopause
• in other hormonal fluctuations

Furthermore, the following influences and behaviors can inhibit histamine breakdown or metabolism:

• Medication intake
• Allergies/ Cross-allergies
• unbalanced diet (e.g., convenience foods, fast food, nutrient-poor foods)
• Nutrient deficiency
• Lack of exercise
• unstable cervical spine or TMJ disorder
• stress

3. Metabolic relief

Since acquired histamine intolerance is in the vast majority of cases due to an overloaded metabolism, we recommend, in addition to a low-histamine diet, intensive support for the main metabolic organs responsible for histamine breakdown. The first main enzyme for histamine breakdown, diamine oxidase (DAO), is located, among other places, extracellularly (i.e., unprotected from external influences and changes) in the intestines. The second main enzyme, histamine N-methyltransferase (HNMT), is located intracellularly (protected), among other places, in the liver. It is therefore essential to restore the balance of these two organs. We apply the following sequence to achieve this:

1. Detoxification of the metabolic organs (intestines and liver)
2. Gut restoration (prebiotics, probiotics, gut-specific nutrition)
3. Liver support (liver-specific diet and supportive supplements)

We place great emphasis on the naturalness of our relief program, as many medications (such as antihistamines) can further burden the metabolism. There are numerous natural antagonists or co-factors that have been proven to promote histamine breakdown and inhibit histamine release from mast cells.