Fermented foods such as sauerkraut, kimchi, cheese, soy sauce, or certain sausages are produced with the help of microorganisms. During these processes, not only lactic acid and other typical fermentation products can form, but also so-called biogenic amines. Histamine is one of these.
However, this does not mean that every fermented food automatically contains high levels of histamine. The actual amount present can vary significantly and depends, among other things, on the raw food, the microorganisms involved, fermentation conditions, and storage.
How is histamine formed during fermentation? Which fermented foods can contain histamine? And why can't the histamine content be determined simply by taste or fermentation time?
What is histamine?
Histamine is a so-called biogenic amine. It occurs naturally in the human body, where it fulfills various physiological functions.
However, histamine can also be found in food. It is often produced through the breakdown or conversion of the amino acid histidine by certain microorganisms.
The decisive factor is the enzyme histidine decarboxylase. Microorganisms that possess this enzyme can convert histidine into histamine.
This exact process can also take place during the fermentation of food.
Why can histamine be formed during fermentation?
During fermentation, microorganisms multiply and alter the components of the raw food.
Some of these microorganisms have the ability to convert certain amino acids into biogenic amines.
In this process, histamine can be formed from histidine.
Whether and how much histamine is formed, however, depends on several factors:
- the raw food
- its amino acid content
- the microorganisms involved
- temperature
- pH value
- salt content
- oxygen availability
- fermentation duration
- hygiene
- storage conditions
This is why even two products of the same category can have very different histamine levels. Current review articles emphasize this high variability in fermented foods.
What role do microorganisms play?
Not every microorganism produces histamine.
For histamine to be formed, microorganisms must be present that can convert histidine using the appropriate enzymes.
This ability can vary even within related bacterial groups. Therefore, it cannot be deduced solely from the statement "fermented with lactic acid bacteria" how much histamine a food contains.
The microbial composition of a fermentation therefore plays a decisive role.
In controlled fermentations, the selection of suitable starter cultures can, among other things, help limit the formation of unwanted biogenic amines.
What are biogenic amines?
Histamine is just one of several biogenic amines that can be formed during microbial processes.
The best-known include:
- histamine
- tyramine
- putrescine
- cadaverine
- phenylethylamine
They are produced through the microbial conversion of certain amino acids.
Fermented foods can therefore contain not only histamine but also various other biogenic amines simultaneously.
This is important because the assessment of a food does not have to depend solely on its histamine content.
Do all fermented foods contain histamine?
No.
Fermented does not automatically mean high in histamine.
For histamine to be formed, there must be, among other things, suitable starting materials and histamine-producing microorganisms.
Furthermore, values can vary greatly even within the same food group.
Scientific studies have sometimes found significant differences between individual products and batches of fermented foods.
Therefore, one cannot say generally, for example:
"Kimchi always contains high levels of histamine"
or
"Sauerkraut is fundamentally low in histamine."
The specific composition can differ from product to product.
Which fermented foods can contain histamine?
Histamine and other biogenic amines have been detected in various fermented food groups.
These include, for example:
- aged cheeses
- fermented sausages
- fermented fish products
- sauerkraut
- kimchi
- fermented soy products like miso or soy sauce
- certain alcoholic beverages
Biogenic amines can play a greater role especially in aged and longer-fermented foods. However, there are also large variations within these groups.
Fermented vegetables and histamine
Histamine and other biogenic amines can also be formed in fermented vegetables.
Studies have been conducted on, for example:
- sauerkraut
- kimchi
- fermented olives
- pickled or fermented vegetables
- fermented soy products
A current review article on plant-based fermented foods shows that the levels depend strongly on raw materials, ingredients, and production conditions. Relevant amounts can be formed in individual products, while others exhibit only low concentrations.
Precisely for this reason, the statement "fermented vegetables contain histamine" is fundamentally possible, but too general to derive a specific amount from it.
Is sauerkraut high in histamine?
Sauerkraut can contain histamine and other biogenic amines.
How high the concentration actually is depends, among other things, on the microbial composition, production, and storage.
Studies show sometimes significant differences between individual fermented products.
Therefore, sauerkraut cannot be reliably classified as "low in histamine" or "high in histamine" based solely on its product category.
Does kimchi contain histamine?
Kimchi is also produced through microbial fermentation and can contain biogenic amines.
The amounts produced are influenced by ingredients, microorganisms, temperature, and fermentation conditions, among other factors.
Kimchi can therefore contain histamine, but the values are not identical for every product.
Does fermentation duration influence histamine?
The duration can play a role – but longer fermentation does not automatically mean more histamine.
The formation of biogenic amines depends on several factors simultaneously.
Even with longer fermentation, histamine is only formed if, for example:
- sufficient histidine is present
- suitable histamine-producing microorganisms are present
- environmental conditions allow for their activity
Therefore, the fermentation duration alone is not a reliable indicator of histamine content.
Does strong fermentation automatically mean high levels of histamine?
No.
Many bubbles, a strong taste, or an intense acidity do not indicate how high the histamine content is.
These characteristics arise from various microbial processes and metabolic products.
Histamine cannot be reliably detected by smell, taste, or appearance.
Therefore, a food can look and taste normal and still contain histamine.
Conversely, a particularly intense fermented taste does not automatically mean a high histamine content.
Can you smell or taste histamine in food?
No.
The histamine content of a food cannot be reliably determined based on:
- smell
- taste
- color
- consistency
- bubble formation
Analytical tests are necessary for an accurate determination.
This distinguishes histamine, for example, from classic signs of spoilage, which can sometimes be visible or detectable by smell.
Are lactic acid bacteria histamine-producing?
Some lactic acid bacteria can produce biogenic amines – but not all of them.
Which ability is present depends on the specific species and sometimes even on the specific strain.
Therefore, the statement "lactic acid bacteria produce histamine" would be too general.
Certain microorganisms possess enzymes for the production of histamine or other biogenic amines, while others do not possess this ability or may even degrade biogenic amines to some extent.
The selection of the microorganisms used is therefore an important starting point in controlled fermentation processes.
Can starter cultures influence histamine formation?
Yes.
In industrially controlled fermentations, specifically selected cultures can be used.
Care can be taken to ensure that the microorganisms used have no or only limited ability to produce biogenic amines.
In addition, research is being conducted into whether certain microorganisms can degrade existing biogenic amines or displace histamine-producing microorganisms.
However, this does not mean that every fermentation with a starter culture is automatically free of histamine.
Can histamine be avoided during fermentation?
A completely histamine-free fermentation cannot be easily guaranteed, especially with spontaneous fermentations.
Certain factors can, however, influence the formation of biogenic amines.
These include, for example:
- high-quality and fresh raw products
- hygienic production
- controlled temperatures
- suitable salt content
- controlled fermentation conditions
- suitable starter cultures
- proper storage
In food production, various strategies are being studied to reduce histamine-producing microorganisms or to degrade biogenic amines that have been formed.
For home-fermented foods, however, the actual histamine content cannot be reliably determined without laboratory analysis.
What is histamine intolerance?
The term histamine intolerance is used for complaints that can occur after the consumption of histamine-containing foods, where an imbalance between ingested histamine and its degradation is discussed.
The scientific classification is complex. Symptoms are non-specific and can have many other causes.
Review articles describe, for example, complaints such as headaches, skin reactions, gastrointestinal complaints, or cardiovascular symptoms. At the same time, there is no single, generally accepted test that can clearly diagnose histamine intolerance.
Recurring complaints should therefore be medically clarified and not self-diagnosed based solely on internet lists.
Why do people react differently to histamine?
The tolerance of histamine-containing foods can be individually different.
Influencing factors can include, among others:
- the actual amount of histamine ingested
- other biogenic amines
- individual degradation capacity
- medications
- alcohol
- health factors
- combinations of different foods
Therefore, the same meal can be tolerated differently by different people.
Are fermented foods fundamentally taboo for histamine intolerance?
A blanket answer is difficult.
Fermented foods are often reduced or initially avoided in low-histamine diet concepts because they can contain histamine and other biogenic amines.
However, this does not mean that every fermented food automatically contains the same amount of histamine or is tolerated equally by every person.
How strictly a diet must be limited should therefore be assessed individually.
Very restrictive and long-term elimination diets should not be carried out without medical or nutritional professional guidance.
Fermentation and histamine: Why food lists only help to a limited extent
Numerous lists can be found on the internet that categorize foods as "low in histamine" and "high in histamine."
For fermented products, however, such a categorization is particularly difficult.
The amount of histamine can vary, for example, between:
- different manufacturers
- production batches
- recipes
- degrees of maturity
- storage conditions
Studies sometimes show large ranges within a single food group.
Such lists can therefore provide at best a rough orientation and cannot replace a concrete analysis of an individual product.
Is histamine in fermented foods dangerous?
Histamine is not fundamentally dangerous.
High amounts can be problematic, especially if foods contain very high concentrations or a person is sensitive.
Histamine poisoning, for example, is known to occur with certain fish products where improper storage can lead to very high concentrations of histamine. High levels of biogenic amines can also be found in fermented products.
However, for normal fermented foods, the risk cannot be assessed across the board based on the term "fermented".
Histamine does not equal spoilage
An important distinction:
Histamine is not a reliable marker for whether a food is visibly spoiled.
A fermented food can contain histamine and still look, smell, and taste normal.
Conversely, a noticeable odor, mold, or other signs of spoilage can indicate a problem, regardless of whether histamine is present.
The questions
"Is this food spoiled?"
and
"How much histamine does this food contain?"
are therefore two different topics.
Frequently asked questions about fermentation and histamine
Why does histamine form during fermentation?
Certain microorganisms can convert the amino acid histidine into histamine with the help of the enzyme histidine decarboxylase. Whether this happens depends on the microorganisms present and the fermentation conditions.
Do fermented foods always contain histamine?
No. Histamine content and the composition of biogenic amines differ greatly between foods and individual products.
Which fermented foods can contain histamine?
Histamine can be found in aged cheese, fermented meat and fish products, sauerkraut, and various fermented soy products, among others. Other fermented foods can also contain biogenic amines.
Does sauerkraut contain histamine?
Sauerkraut can contain histamine and other biogenic amines. However, the concentration can differ significantly depending on the production conditions and the product.
Does long fermentation automatically mean more histamine?
No. The fermentation duration is only one of several influencing factors. Other decisive factors include, for example, the microorganisms, the raw food materials, temperature, salt content, and storage.
Can I tell how much histamine is in a food?
Not reliably. Histamine cannot be determined by taste, smell, or appearance. An accurate measurement requires an analytical examination.
Do all lactic acid bacteria produce histamine?
No. The ability to form biogenic amines differs between different microorganisms and strains.
Is home-fermented vegetable higher in histamine?
This cannot be said generally. In spontaneous fermentations, the microbial composition is less standardized, but the actual histamine content cannot be safely predicted for either home-made or store-bought products without analysis.
Should you avoid all fermented foods if you have a histamine sensitivity?
Not necessarily across the board. The tolerability and histamine content of individual products can vary greatly. In the case of recurring complaints, an individual medical or nutritional assessment is advisable.
Conclusion: Fermentation can form histamine – but does not have to
During fermentation, microorganisms can form numerous metabolic products. Under certain conditions, this includes histamine and other biogenic amines.
The decisive factor, however, is differentiation:
Not every fermented food automatically contains a lot of histamine.
How much histamine is produced depends on the raw food, microorganisms, fermentation conditions, and storage, among other things. Significant differences can therefore occur even within a single product group.
Taste, smell, or fermentation duration also do not allow for a reliable assessment of histamine content.
For people who tolerate fermented foods well, their histamine content is therefore not automatically problematic. Conversely, anyone who repeatedly observes symptoms after consuming histamine-containing or fermented foods should have this clarified individually by a medical professional or nutritionist.
Especially when it comes to the topic of histamine, a blanket classification into "good" or "bad" is therefore not very helpful. What is decisive is the specific food, its production, and individual tolerability.