Histamine intolerance: causes, symptoms and dietary tips

Do you suffer from redness, itching, headaches or digestive problems after eating certain foods? Then you could be affected by histamine intolerance. With this food intolerance, the body is unable to break down excess histamine - a biogenic amine - sufficiently. The symptoms often resemble an allergy, but unlike a genuine allergic reaction, it is not caused by a misdirected immune system, but by an imbalance in the histamine balance. In this article, you will find out how histamine intolerance occurs, what symptoms can occur, how it differs from a "histamine allergy" and how you can get your symptoms under control with a low-histamine diet.

Causes and mechanisms of histamine intolerance

Histamine intolerance (also known as enteral histaminosis) occurs when more histamine is produced in the body than can be broken down. Histamine itself is mainly produced by the breakdown of the amino acid histidine. In many foods - especially protein-rich foods such as fish or cheese - bacteria convert histidine into histamine during maturation or storage. Spoiled fish or fermented products, for example, can accumulate enormous amounts of histamine. Normally, the enzyme diamine oxidase (DAO) in the small intestine ensures that histamine ingested with food is broken down quickly. However, if there is a lack of DAO - for example due to genetic predisposition, damage to the intestinal mucosa or DAO-blocking medication - this system becomes unbalanced. The result is an excess of histamine in the body, which triggers the various symptoms of histamine intolerance.

Several factors can lead to a functional DAO deficiency. Some medications (for example certain painkillers, antibiotics or antidepressants) inhibit DAO activity or lead to the release of histamine. Alcohol is also a doubly problematic factor: on the one hand, red wine in particular contains considerable amounts of histamine, on the other hand alcohol inhibits the DAO and can stimulate mast cells to release the body's own histamine. All in all, even a small amount of alcohol can cause significant reactions in people with histamine intolerance.

In addition to alcohol, other foods are considered histamine liberators. This means that although they contain little histamine of their own, they can trigger the release of histamine in the body. These triggers include citrus fruits, certain seafood, papaya, tomatoes, nuts (including cashews), pineapple, spinach, chocolate and strawberries. The exact mechanisms behind this are not yet fully understood scientifically. If you notice that such foods cause you discomfort, it can be useful to keep an eye on them too, even though their own histamine content is low.

An important indication that an imbalance in histamine breakdown is the cause of the symptoms is provided by the observation that the symptoms of affected women often improve significantly during pregnancy. During pregnancy, the body (more precisely: the placenta) produces enormous amounts of DAO - the DAO level in the blood increases up to 150-fold. As a result, excess histamine is broken down much more effectively. Many women with histamine intolerance find that they have fewer or no symptoms during this time. This phenomenon underlines the central role of diamine oxidase: if sufficient DAO is present, histamine remains in balance in the body.

In summary, it can be said that the main cause of histamine intolerance is inadequate metabolism of histamine due to a lack of DAO activity. This can be congenital or exacerbated by external factors. In addition, certain foods can act as histamine liberators or contribute a lot of histamine themselves - causing the "barrel" of histamine to overflow and the tolerance threshold to be exceeded. This is precisely when the various symptoms become noticeable.

Symptoms: How does histamine intolerance manifest itself?

Histamine acts at different points in the body and can therefore cause a whole range of symptoms. Many sufferers do not initially recognize any connection to food, as the symptoms are varied and do not always occur immediately after eating. Typical symptoms of histamine intolerance can be

• Skin and mucous membranes: redness, a feeling of warmth or sudden flushing on the face and neck, itching, hives (urticaria) and swelling. Excruciating skin rashes or eczema can also be caused by excess histamine. Many people report that the symptom "red spots on the neck and face" is particularly noticeable after a glass of wine or a histamine-rich meal.
• Digestive tract: abdominal pain, cramps, flatulence, diarrhea or nausea after eating. Histamine affects the intestinal muscles and secretion - too much can lead to accelerated bowel movements (diarrhea) or heartburn. Digestive symptoms sometimes only occur hours after a meal, which makes it difficult to find the cause.
• Cardiovascular system: Histamine causes blood vessels to dilate. This can lead to low blood pressure, dizziness and an accelerated pulse (tachycardia). Some sufferers experience heart palpitations or even mild cardiac arrhythmia after consuming histamine-rich foods. Headaches or migraine-like attacks are also frequently reported symptoms - partly due to the drop in blood pressure, partly due to the direct effect of histamine on pain receptors. Histamine can also cause the nasal mucous membranes to swell, so that a runny or blocked nose (without a cold) is possible after eating.
• Nervous system: Histamine also acts as a neurotransmitter in the brain. Too much can cause restlessness, sleep disorders or dizziness. Severe headaches or migraines often occur - these are among the most common symptoms of histamine intolerance. Those affected often feel unusually tired or "dizzy" after eating histamine-rich foods.

The **symptom intensity** can vary greatly from person to person. Some people react to even the smallest amounts of histamine with severe symptoms, while others can still tolerate a certain amount. As a result, histamine intolerance sometimes goes unrecognized for a long time because the symptoms are non-specific and also fit other intolerances or illnesses. It is important to note that if such symptoms occur repeatedly, especially after eating certain foods (e.g. mature cheese, red wine or sauerkraut), you should consider a suspected histamine intolerance. A food diary over several weeks often helps to uncover the connection between diet and symptoms.

Histamine intolerance vs. "histamine allergy": what's the difference?

The term histamine allergy is occasionally bandied about on the internet, but strictly speaking it is incorrect. You cannot be allergic to histamine in the classic sense, because an allergy means that your immune system produces antibodies (IgE) against a substance that is actually harmless (for example, a food protein or pollen). However, histamine is not a foreign substance, but a molecule produced naturally in the body that is present as a messenger substance in every human being. In the case of a genuine food allergy, the body releases histamine as a reaction to the allergen - this histamine is then the mediator of the allergy symptoms (redness, swelling, itching, etc.). This is probably the root of the misleading term "histamine allergy" - the symptoms look like an allergy, but there is no external allergen to which the immune system reacts. Instead, it is an intolerance, i.e. a non-immunological hypersensitivity. In histamine intolerance, the excess histamine in the body is not sufficiently broken down, whereas in an allergy, normal histamine is released because an immune reaction has been triggered. These are therefore two completely different mechanisms.

Important for you to know: An allergy test (prick test or IgE antibody test) is usually negative in the case of pure histamine excess, as there is no specific allergy. This can be frustrating if you go to the doctor with allergy symptoms but no allergen is found. Histamine intolerance is a diagnosis of exclusion, which means that it is often only diagnosed in practice after allergies and other causes have been ruled out. One indication may be lowered DAO enzyme levels in the blood or a positive effect of a low-histamine diet.

Remember: The term "histamine allergy" is not medically correct. It is an intolerance or pseudo-allergy, in which no immune system acts against histamine, but an enzyme deficiency or a disturbed degradation pathway is the cause. The treatment is therefore also fundamentally different: instead of allergen avoidance and emergency kits (as with a genuine allergy), the main focus with histamine intolerance is on diet.

Histamine-rich foods: what does histamine contain?

Histamine is found in many foods in very different concentrations. Some foods contain practically no histamine, others can contain enormous amounts. Freshness, processing and ripening time play a decisive role here. Generally speaking, the longer a food has been matured, fermented or stored, the higher its histamine content. Freshness, on the other hand, is your friend with histamine intolerance.

The best-known histamine-rich foods include

• Matured cheeses: Hard and semi-hard cheeses such as Emmental, Parmesan, Cheddar, Camembert or Roquefort usually contain a lot of histamine as they mature for a long time. The older the cheese, the more histamine may have accumulated. Fresh cheeses (e.g. cottage cheese, ricotta or quark) and young Gouda contain significantly less histamine and are often better tolerated.
• Fermented dairy products: In addition to cheese, fermented cream or kefir is also high in histamine. Yoghurt contains moderate amounts of histamine - some histamine intolerant people can tolerate small amounts of yoghurt, others have problems even with yoghurt. Butter and normal pasteurized milk, on the other hand, are low in histamine as they are not fermented. **Milk** itself contains hardly any histamine, but is still poorly tolerated by some sufferers, possibly due to other ingredients. Individual caution is required here.
• Sausage and cured meat: Salami, ham, bacon, smoked or cured meat are histamine-laden due to maturing or storage. Dried meat products (beef jerky, Bündnerfleisch etc.) also accumulate histamine. Freshly prepared meat (uncured, unfermented), on the other hand, is low in histamine - but make sure to keep it well chilled and consume it soon, as the histamine content quickly rises when it starts to spoil.
• Fish (especially not absolutely fresh): Fish is naturally rich in histidine. As soon as a fish is no longer completely fresh, bacteria begin to convert histidine into histamine. Tuna, mackerel, sardines and other types of fish can develop a lot of histamine if not stored properly. Histamine poisoning (scombroid fish poisoning) are acute cases in which spoiled fish has extremely high histamine levels. But even below the poisoning threshold, canned fish or smoked fish can contain histamine levels that are problematic for histamine intolerant people. For example, canned samples of mackerel or tuna have been found to contain over 500 mg of histamine per kg - in comparison: fresh fish often contains less than 1 mg/kg. The following therefore applies to fish: only consume absolutely fresh fish or freeze it immediately.
• Wine and beer: Alcoholic drinks, especially red wine, sparkling wine/champagne and beer, are frequent triggers of histamine symptoms. Depending on the variety and production process, red wine can contain considerable amounts of histamine (values above 10 mg/L are possible). Beer also contains histamine due to yeast and fermentation, although top-fermented beers (such as wheat beer) tend to contain more than bottom-fermented beers. Wine and beer should be consumed with caution or avoided in the case of histamine intolerance. White wine often contains slightly less histamine than red wine, but is also not histamine-free. Important: Alcohol also increases the effect of histamine and inhibits its breakdown, which further reduces tolerance.
• Vinegar and fermented vegetables: Balsamic vinegar, red wine vinegar and vinegar in general (which is produced by fermentation) contains histamine. Fermented products such as sauerkraut, kimchi, pickled cucumbers or soy sauce are also very high in histamine. Soy sauce and other fermented soy products (miso, tempeh) can reach peak levels - in some analyses, the histamine content of soy sauce was over 1000 mg/kg. Unfermented soy products such as tofu or soy milk, on the other hand, are relatively low in histamine and often well tolerated.
• Tomatoes, eggplants and spinach: These vegetables have a naturally low histamine content, but this can increase slightly during storage. Although tomatoes and spinach are not comparable to fermented foods, many sufferers report that they do not tolerate them well. As mentioned, tomatoes are also considered to be possible histamine liberators. If you are very sensitive, carefully test whether you can tolerate small amounts of fresh tomatoes. Cooked tomato sauce (which has been left to stand longer or is canned) is usually more critical than fresh tomatoes.
• Nuts and pulses: Nuts that have been stored for a long time or are not completely fresh (walnuts, cashews, peanuts) may contain or release some histamine due to storage conditions. Cashews are listed as problematic in some lists - presumably not so much because of their high histamine content, but rather because they act as a liberator for some people. Dried pulses such as beans, lentils and chickpeas are histamine-free when dried, but can produce some histamine during long storage or sprouting. Cooked beans are not normally critical, unless they are canned (where they may show traces due to storage time). As a rule of thumb, nuts and beans are usually well tolerated when fresh and in perfect condition, but individual differences are possible.
• Other potential problem cases: chocolate (due to biogenic amines such as phenylethylamine and possible histamine liberation), ripened bananas (slightly increased histamine when fully ripe and possible liberator effect), avocado (slightly increased due to ripening), citrus fruits (liberator effect), strawberries (liberator), pineapple and papaya (have their own enzymes, possibly liberator). Spices such as cinnamon, nutmeg or chili are also occasionally described as triggers, presumably because they can irritate mast cells. The individual tolerance threshold plays a major role here.

The list of potentially problematic foods is long - but that doesn't mean you can never eat all these things again. Many sufferers have different tolerance thresholds. What triggers symptoms in one person may still be tolerated by another. It is therefore important that you identify your personal "trigger foods". A food diary can help you determine which foods you react to. Often it's the usual suspects (such as red wine or cheese), but sometimes individual peculiarities surprise you - one person can tolerate some lemon juice, for example, while another can't; instead, some ripe Camembert may work in small quantities, while sauerkraut doesn't work at all.

Nevertheless, there are some foods that practically all experts recommend avoiding in the case of histamine intolerance. A review comparing different dietary recommendations found that fermented foods such as aged cheese, wine and beer were mentioned in all diets as foods to be strictly avoided - so there is a consensus here. For most other foods, there were differences between the recommendations, reflecting the inconsistent data and individual differences. This shows that strict bans beyond the "prime suspects" are not set in stone. You don't have to lead a completely monotonous life, but it is worth reducing the histamine-rich foods mentioned above as much as possible.

Low histamine diet: tips and special features

The most important measure for histamine intolerance is a low-histamine diet. By carefully selecting and preparing foods, you can significantly reduce your histamine intake and thus reduce your symptoms. Here are some tips and advice on how you can adapt your diet accordingly:

Freshness is the be-all and end-all

The fresher the food, the lower the histamine content. Buy as fresh produce as possible and process or consume it soon. For meat and fish in particular, it is best to prepare them the same day or freeze them immediately. Prolonged marinating or storing leftovers at refrigerator temperature can lead to the formation of histamine. If you pre-cook or have leftovers, freeze them instead of keeping them in the fridge for several days.

Suitable and less suitable foods

Basically, your food can be divided into tolerable (low histamine) foods and problematic (high histamine) foods. Here is a rough guide:

• Low histamine foods (well tolerated): Fresh meat and fresh fish (if directly processed), eggs, fresh milk (if well tolerated, as it is low in histamine), many vegetables (e.g. carrots, broccoli, zucchinis, peppers - unless they are overripe or have been stored for a long time), salads, gluten-free cereals and pseudocereals (rice, corn, millet, quinoa), but also wheat, spelt, rye and especially oatmeal are naturally low in histamine. Oat flakes are mentioned as problematic in some internet sources, but in fact they do not contain any histamine. You should only react if you have an individual oatmeal intolerance - in general, oats & co. are well suited. Fruit is also largely low in histamine, especially if it is fresh and ripe, but not overripe. Apples, pears, grapes, kiwi and watermelon, for example, are well tolerated. Sugar, honey or maple syrup are histamine-free sweeteners (enjoy in moderation). Vegetable oils and fats do not contain histamine. Fresh herbs are harmless.
• Histamine-rich or triggering foods (enjoy carefully or avoid): Matured cheese, salami, ham, smoked fish, canned fish, seafood, yeast extract, fermented soy (soy sauce, tempeh, miso), sauerkraut and other fermented vegetables, vinegar, alcoholic beverages, overripe fruit (brown bananas, very ripe pineapple, strawberries in large quantities), tomatoes, eggplants, spinach, citrus fruits, nuts (if not completely fresh) and heavily processed ready-made products with long lists of ingredients (may contain additives that release histamine or inhibit its breakdown). Note that spice mixes or instant products sometimes also contain hidden histamine-rich ingredients (e.g. yeast extract). If in doubt, read the labels carefully.

These lists are of course not exhaustive, but they will give you an idea. It is important that you don't just rely on lists, but try out what you personally tolerate. Ideally, you should start by following a consistent low-histamine diet for 2-4 weeks. If your symptoms improve significantly during this time, you have a strong indication that histamine is the cause. You can then find out where your limits lie by carefully testing individual foods. For example, you may be able to tolerate small amounts of a certain type of cheese or a small glass of sparkling wine without any major problems - you can use this kind of individual leeway as soon as you feel better overall. However, the basis of your diet should remain low in histamine so as not to provoke symptoms again.

Special: coffee, coconut milk, quark & co.

Some foods are repeatedly asked by those affected whether they are permitted with histamine intolerance. Here are a few of them:

• Coffee: Pure coffee contains no histamine. Nevertheless, some people report that they cannot tolerate coffee well. The reason could be that caffeine can promote the release of the body's own histamine or that coffee contains many acids that irritate the intestines. If you notice that coffee causes you problems, try switching to decaffeinated coffee as a test - some histamine intolerant people tolerate it better. As a general rule: if you consume a moderate amount (1-2 cups) and tolerate it well enough, you don't necessarily have to give up coffee. Listen to your body here. If you are unsure, herbal or grain coffee is a low-histamine alternative.
• Coconut milk: Unlike animal cream, coconut milk is not fermented and is considered low in histamine. Many people use coconut milk as a substitute in recipes to avoid cream. Most histamine intolerant people tolerate coconut products (coconut milk, coconut oil, shredded coconut) very well. They contain neither histamine nor known liberators. You can therefore incorporate coconut milk into your recipes as you wish - it is a great alternative for creamy dishes.
• Quark: Quark (curd cheese) is a freshly produced dairy product and, unlike hard cheese, is only fermented for a short time. Quark therefore contains significantly less histamine than long-matured cheeses. Many sufferers can eat quark in moderate quantities, some even better than yoghurt. However, make sure to keep quark fresh - the histamine content can slowly increase if it is stored for a long time (especially after opening). Compared to mature cheese, however, quark is one of the milky options that are often possible.

Diamine oxidase as a helper: DAO supplementation

Some people with histamine intolerance turn to DAO enzyme capsules in addition to their diet to help their body break down histamine. These capsules contain the enzyme diamine oxidase, usually obtained from plant or animal sources. The idea behind them: If you take a DAO capsule before a meal containing histamine, the additional enzyme in the small intestine can help break down some of the histamine from the food before it causes symptoms. In fact, initial studies show that DAO supplementation can alleviate the symptoms of histamine intolerance. In a study of histamine intolerant patients who took DAO capsules for 4 weeks, the frequency and intensity of symptoms were significantly reduced. As soon as the intake was stopped, the symptoms increased again - indicating that the enzyme helped temporarily.

DAO capsules are available in the EU as a food supplement or food for special medical purposes. The European Food Safety Authority (EFSA) has approved an extract containing DAO (obtained from pig kidneys) as a novel food ingredient. This shows that such supplements are generally considered safe. Nevertheless, DAO supplementation is not a free pass to consume unlimited amounts of histamine. Rather, it can be a supportive measure, e.g. if you eat out or want to enjoy something rich in histamine. The basic therapy remains the low-histamine diet. It is the "gold standard", so to speak, while DAO preparations can be an additional tool. It is also important to have realistic expectations: Not everyone feels a clear effect from DAO capsules; for some it helps, for others less so. It is worth trying them out individually (ideally in consultation with a doctor).

Finally, a word about antihistamines: these drugs block the effect of histamine at the receptors. H1 antihistamines (such as cetirizine or loratadine) can relieve acute symptoms - many histamine intolerant people have them as emergency medication or take them daily during difficult phases. In the long term, however, this should only be done in consultation with a doctor. It should also be noted that antihistamines themselves can have side effects. Interestingly, one of them is often weight gain. Why? Histamine acts as a signaling substance in the brain which, among other things, curbs the appetite. If the histamine effect is blocked (by antihistamines), the appetite can increase. Studies have shown that people who regularly take antihistamines have a higher average body weight. This doesn't mean you should avoid antihistamines altogether - they are a helpful tool. But it does explain part of the connection between histamine intolerance and weight problems, which we will come to in a moment.

Histamine intolerance and weight problems

Many health-conscious people wonder whether there is a link between histamine intolerance and weight problems. In fact, it is reported that some sufferers have difficulty losing weight or even gain weight unintentionally. The causes of this can be varied and indirectly related to the histamine problem:

• As mentioned above, frequent antihistamine use can contribute to weight gain as it can increase your appetite and slow down your metabolism. So if you regularly take allergy medications because of your histamine intolerance, this could be a factor in changes in your weight.
• A very restricted diet due to histamine intolerance can also have paradoxical effects. On the one hand, you might think that fewer food choices automatically lead to less calorie intake. On the other hand, those affected tend to switch to "safe" but possibly higher-calorie foods. For example, fresh meat and rice are well tolerated - but if you eat mainly meat with rice and leave out salads, tomatoes, lots of fruit etc., your diet can become more one-sided and potentially more energy-dense. Also, giving up histamine-containing pickles, sauerkraut or cheese sometimes leads to more bread, pasta or sweets being eaten as a substitute. This can ultimately lead to weight gain, even though you are actually doing without many things.
• Some people with histamine intolerance also suffer from other intestinal problems or inflammation in the body. A permanently irritated gut can lead to suboptimal nutrient absorption and metabolic changes. Chronic inflammatory processes (to which histamine can contribute) are suspected of slowing down metabolism and impairing insulin sensitivity - factors that can make losing weight more difficult.
• On the other hand, some also report weight loss when symptoms are severe. Constant diarrhea or loss of appetite after meals can lead to an overall low calorie intake and unwanted weight loss. In such cases, it is important to ensure a sufficient intake of nutrients and calories by eating suitable foods to prevent malnutrition.

To summarize: histamine intolerance can have an indirect effect on body weight. Some sufferers have difficulty maintaining or reducing their weight, while others are more likely to become underweight. It is important to eat a balanced diet and not to eat a one-sided diet for fear of histamine. If you notice weight problems in connection with histamine intolerance, it is worth talking to nutritionists or doctors. If necessary, they can help you draw up a diet plan that is both low in histamine and balanced. Don't forget: Adequate exercise and general lifestyle factors naturally also play a role in weight - despite histamine intolerance.

On a positive note, many people find that once they have their histamine intolerance under control (through diet and possibly support such as DAO capsules), their body weight also regulates better. You feel better overall, have more energy for sport and everyday life again and can therefore reach your feel-good weight more easily. Histamine intolerance doesn't have to be a permanent obstacle to your health goals - it just requires a little self-observation and lifestyle adjustment.

You can find our DAO capsules here.

FAQ about histamine intolerance

What exactly is histamine intolerance?

Histamine intolerance is an intolerance to histamine, an endogenous and food-related messenger substance. It occurs when your body cannot break down enough histamine - usually due to a lack of the enzyme diamine oxidase (DAO). In contrast to an allergy, the immune system is not involved in histamine intolerance.

What are the typical symptoms of histamine intolerance?

Typical symptoms include reddening of the skin, hives, headaches, migraines, digestive problems such as diarrhea or abdominal pain, palpitations, low blood pressure and breathing difficulties. Neurological symptoms such as dizziness or sleep disorders can also occur.

How does histamine intolerance differ from a histamine allergy?

Histamine intolerance is caused by an enzymatic disorder - your body cannot break down histamine sufficiently. In the case of a histamine allergy (correctly: an allergy to histamine-releasing substances), the immune system would produce antibodies, which is not the case here. Histamine intolerance is therefore a pseudo-allergy, not a real allergy.

Which foods contain particularly high levels of histamine?

In particular, fermented and matured products such as matured cheese, red wine, beer, sauerkraut, salami, canned tuna and fermented soy sauce contain a lot of histamine. Tomatoes, spinach, eggplants and nuts that have been stored for a long time can also be problematic.

Are there foods low in histamine?

Yes, fresh meat, fresh fish (directly processed), eggs, many fresh vegetables such as carrots, broccoli, zucchinis, peppers and gluten-free cereals (rice, millet, quinoa) are considered to be low in histamine. Fresh, not overripe fruit such as apples or pears are also usually well tolerated.

Does a low-histamine diet help with histamine intolerance?

Definitely. A low-histamine diet is the basis of treatment. By avoiding histamine-rich foods and individual triggers, you can usually significantly reduce your symptoms. A food diary helps to identify personal triggers.

Can I drink coffee if I have a histamine intolerance?

Pure coffee contains hardly any histamine, but can still trigger symptoms in sensitive people, as caffeine can promote the release of histamine. Some people tolerate decaffeinated coffee better. It is best to test how you react to coffee individually.

What are histamine liberators?

Histamine liberators are foods that contain little histamine themselves but can release the body's own histamine. These include citrus fruits, strawberries, chocolate, tomatoes and some seafood.

Why can histamine intolerance lead to weight problems?

Antihistamines, which are often used for histamine intolerance, can increase appetite and slow down the metabolism. In addition, unbalanced eating patterns due to strict diets can affect weight. A balanced, low-histamine diet is therefore particularly important.

How is histamine intolerance diagnosed?

A clear diagnosis is difficult. It is usually made by ruling out other diseases, documenting the symptoms precisely, possibly determining the DAO activity in the blood and successfully improving symptoms on a low-histamine diet.

Can histamine intolerance be cured?

Currently, histamine intolerance cannot be cured, but it can be controlled very well. With an individually adapted diet, possibly supported by DAO supplements, you can live symptom-free in the long term.

Sources

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