Ripened cheeses can contain large amounts of histamine, a molecule that accumulates in fermented foods, causing gastrointestinal symptoms and headaches.
Surprising as it may seem, almost 90% of migraines could be caused by the inability to metabolize the histamine contained in certain foods such as cheese or sausages. That is, the same molecule that causes allergic reactions to pollen, cat hair and nuts, to give a few examples.
Histamine performs important biological functions, since it participates in the immune response, in the regulation of local circulation or in the secretion of stomach acids, among other processes. It is synthesized in certain cells of the body itself, where it is stored until it is used. It’s largely removed by an enzyme called diamine oxidase, or DAO, which breaks it down when it’s no longer needed.
However, we can also come into contact with histamine by eating fermented foods (cheese, wine, sausages…) or products such as fish when they have been poorly preserved. This is because the microorganisms present in these foods can also produce histamine.
Headache and hives
A high percentage of the population fails to efficiently metabolize histamine. For this reason, shortly after its intake, as its concentration in the blood increases, it is not uncommon to experience symptoms such as headache, nausea, tachycardia or hives. In more severe cases, bronchospasm and even cardiac arrest may appear.
In addition, approximately 1% of the population is intolerant to histamine, that is, they cannot eliminate it effectively. This is usually due to a deficit or a malfunction of the DAO. For these individuals, consuming foods with a large amount of histamine can be fatal to their health.
The histamine of matured cheeses
There is a European standard that regulates the amount of histamine present in fish and derivatives, and that establishes a limit of 200 mg per kilo (mg/kg) of product (Regulation (EU) No. 2073/2005). However, there is no regulation to date that controls the amount of histamine present in dairy products. Ripened cheeses can contain significant amounts of histamine, even up to 2,500 mg/kg.
The European Food Safety Authority (EFSA) has proposed a daily intake of 25-50 mg as the maximum safe dose for healthy people. For its part, the World Health Organization (WHO) has indicated that 50 mg is the maximum dose of histamine ingested without adverse effects. What is clear is that there is a general consensus at the health level on the need to set a maximum in the consumption of histamine.
We have analyzed the amount of histamine present in dairy products available in Spanish supermarkets and neither milk nor yogurt nor kefir contain high amounts of histamine. However, it is very striking that almost a third of the cheeses of different varieties and types contain more than 200 mg/kg of this substance, some of them exceeding 500 mg/kg. Its excessive consumption, according to EFSA, could be harmful or even toxic.
It must be considered that if we eat a serving of cheese (about 30 grams), we would not take more than 15 milligrams of histamine. In healthy individuals, this intake would not cause adverse effects, although it could in people with DAO deficiency or histamine intolerance.
More histamine in the center of the wedge than next to the crust
Hard or semi-hard cheeses, mainly raw and sheep or goat milk, usually contain a higher amount of accumulated histamine. It could be recommended to reduce its consumption in the most sensitive people to avoid migraines and other gastrointestinal symptoms.
Also, histamine appears to accumulate in the center of the wedge, rather than near the cortex. Thus, it could also be recommended to avoid eating the central area of the cheese wedge to minimize these associated symptoms.
Another way to tackle the problem would be to make changes to your production. We might think that the histamine in cheese is generated by the bacteria that we add to ferment the milk and produce the cheese. However, its main origin is contaminating microorganisms that reach the final product from raw materials (milk, salt…) or from the production machinery itself, such as Lentilactobacillus parabuchneri or Tetragenococcus halophilus, among others.
Hygiene, DAO and bacteria
Bearing this in mind, to prevent cheeses with a large amount of histamine from reaching the supermarket, measures could be taken to prevent the production of this molecule during the fermentation process. For example, by improving hygienic conditions during milking or by carefully selecting the added fermenting bacteria so that they are not capable of generating histamine.
In addition, once the cheeses are produced, during the ripening process, it would be possible to better control conditions such as pH, the amount of salt or the ripening temperature, to prevent the bacteria present from producing histamine.
Finally, if the DAO enzyme is added during fermentation, or bacteria with the ability to eliminate histamine, cheeses with a low content of this substance could be obtained. A team of Spanish researchers have been able to produce matured cheeses with up to 40% less histamine just by adding to the milk the same bacteria that produce yogurt (Lactobacillus bulgaricus together with Streptococcus thermophilus) or some yeasts (Debaryomyces hansenii) that help to its maturation.
Taking steps to obtain a range of dairy products that are low in histamine is important. Because it would solve a public health and food safety problem that is little known but of great magnitude.
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