Letzte Aktualisierung am 8. December 2023 von Dr. Michael Zechmann-Khreis
Histamine intolerance, also known as histamine intolerance, is the condition when there is too much histamine in the body and problems occur as a result. Histamine is a biogenic amine and a very important substance that must be present in the body, where it fulfills important tasks. However, if there is an imbalance between histamine absorbed through food and histamine-degrading enzymes, symptoms can occur. This is called histamine intolerance. This imbalance can be caused by a reduced activity of the enzyme diamine oxidase (DAO), as well as by increased intake of biogenic amines through food, by production of biogenic amines by the body’s own intestinal bacteria and by external inhibitors (i.e. inhibitors). Another enzyme (HNMT, see below), which breaks down histamine in the body, may also play a role. The consequences are symptoms such as reddening of the skin, abdominal pain, diarrhea, etc. However, not all of these triggers have to occur at the same time. The range of symptoms is very variable.
Frequency of histamine intolerance
Histamine intolerance occurs in approx. 1-3% of the population. According to a study by the nmi portal, however, the number of unreported cases is very high, i.e. there are probably more people affected. According to a study by Jarisch, around 80% of those affected are women, most of them over the age of 40. This trend could not be verified in the nmi portal survey.
Two types of histamine intolerance
Histidine (a natural amino acid) is broken down to histamine by bacteria (or yeast) in food. This is then broken down in the human body by the enzymes diamine oxidase (DAO, outside the cells; found in the small intestine) and N-methyl transferase (HNMT, inside cells; for example in the liver). Enzymes are molecules that help the body to carry out certain reactions. They can, for example, cleave other molecules or help to convert one molecule into another.
Diamine oxidase type – DAO
A healthy person produces diamine oxidase (DAO) as soon as they consume food. The DAO is released directly into the intestinal lumen, i.e. the area where food enters. This means that the histamine can already be “neutralized” in the intestine. Of course, this only works up to a certain limit. If too much histamine is ingested (for example, spoiled food – often spoiled fish), the typical symptoms of “histamine poisoning” also occur in a healthy person. This is called food poisoning. However, if too little DAO is generally produced, e.g. because the intestine is damaged, even small amounts of histamine can cause these symptoms.
The DAO enzyme needs the help of copper and vitamin B6 to function properly. In a “DAO type” histamine intolerance, the activity of diamine oxidase (DAO) is restricted. This may also be due to a copper or B6 deficiency. This can be determined by the doctor in a blood count.
Caution: DAO can be tested in blood, stool or urine, but the quantities found there cannot be used for diagnosis !
DAO and pregnancy
Women repeatedly report that their histamine intolerance disappears during pregnancy and reappears after the birth. This is due to the fact that DAO is produced by pregnant women in very large quantities. The DAO is increasingly released into the bloodstream in order to protect the child from possible histamine surpluses.
Type HNMT
HNMT occurs more frequently in organs such as the liver, skin, respiratory tract and central nervous system. The HNMT inhibits itself, i.e. the more it is present, the less active it is. This mechanism is important because the body wants to regulate histamine. We need histamine in the body, so the body doesn’t want to break it down completely, it just wants to regulate it. If a lot of histamine is present, a lot of HNMT is produced. The more HNMT, the less effect it has. If a lot of histamine is then also ingested with food or released in the body through other mechanisms, this can lead to an excess of histamine, which cannot be broken down at the moment because the HNMT inhibits itself. This “HNMT type” causes a gradual and slow accumulation of histamine in the body. The symptoms of this type are often less noticeable but last longer.
The breakdown of histamine is also promoted by vitamin C. Taking vitamin C can improve the symptoms in some patients. Please be sure to discuss vitamin C intake with your doctor!
Sources on histamine intolerance (among others)
1) Jarisch, R.,2004: Ärztemagazin 08/2004, Histamine intolerance
2) Jarisch, R. “Histaminunverträglichkeit”, Thieme Verlag TB 2nd edition
3) Schmutz Helmut (author); Abbot, G.; Lieners C.; Mayer, I.; et.al; “Nahrungsmittelunverträglichkeit (Histamin Intoleranz)”, non-fiction book, Vienna 2006
4) Sattler, J; Hafner, D; Klotter, HJ; et.al;“Food-induced histaminosis under diamine oxidase (DAO) blockade in pigs: Further evidence of the key role of elevated plasma histamine levels as demonstrated by successful prophylaxis with antihistamines“; Agents and Actions; Volume 27, Numbers 1-2 / April 1989
5) Maintz L, Yu C-F, Rodriguez E, et.al.“Association of single nucleotide polymorphisms in the diamine oxidase gene with diamine oxidase serum activities“, Allergy 2011
6) Stryer, L., Biochemistry, Specktrum Akademischer Verlag, 4th edition
7) Beliz, H.D., Textbook of Food Chemistry, Springer Verlag, 2001
8) P. Velicky, K. Windsperger, K. Petroczi, S. Pils, B. Reiter, T. Weiss, S. Vondra, R. Ristl, S. Dekan, C. Fiala, D. E. Cantonwine, T. F. McElrath, B. Jilma, M. Knöfler, T. Boehm, J. Pollheimer: Pregnancy-associated diamine oxidase originates from extravillous trophoblasts and is decreased in early-onset preeclampsia. In: Scientific Reports. Vol. 8, No. 1, April 20, 2018, doi:10.1038/s41598-018-24652-0.
