Histamine N-methyltransferase (HNMT) degradation disorder
Histamine N-methyltransferase, or HNMT for short, is an endogenous enzyme. Why is this enzyme so important in the context of histamine intolerance? An HNMT degradation disorder means that histamine cannot be properly broken down. In this blog article, you will learn about the processes that occur in your body with such a degradation disorder and helpful tips.
How does histamine intolerance manifest itself?
- typical and cutaneous: skin redness, itching, flushing, hives
- respiratory: stuffy nose, asthma attacks, runny nose
- gastroenterological: diarrhea and constipation, bloating, abdominal pain
- cardiac: cardiac arrhythmias, low blood pressure, high blood pressure
- headaches and menstrual pain
- dizziness, nausea, and vomiting
DAO deficiency and symptoms
The enzyme DAO is considered one of the most important degradation pathways for histamine in the human body. It primarily acts in the intestine by breaking down extracellular histamine, especially from food, already in the chyme. The enzyme is not particularly well protected from external chemical influences, as it is excreted from the cell interior into the intestine, where there is no longer any protection from the substances occurring there. If there is a DAO deficiency, there is an excess of histamine and thus histamine-related symptoms.
Since DAO plays an important role in the breakdown of histamine from food, targeted supplementation may be useful in certain situations. Our DaoFit contains vegan DAO from pea sprout powder as well as vitamin C from acerola and quercetin. It is suitable as a supplement before histamine-containing meals and is suitable for a low-histamine, low-fructose, gluten-free, and lactose-free diet.
Lieferzeit: 2-3 Tage
HNMT degradation disorder and symptoms
- temporary or acquired reduction in activity due to external factors such as medication (HNMT blockers), an overburdened liver, nutrient deficiencies, or chemical environmental influences such as heavy metal contamination.
- genetically determined, i.e., permanent HNMT deficiency or permanent functional impairment
INFO: Most of the time, reduced HNMT activity occurs because various causes add up. Many sufferers also have problems with histamine breakdown in the intestine.
The effect of HNMT compared to DAO
In the organs where HNMT acts, there is a particularly high number of mast cells. If the symptoms manifest particularly in the liver, kidneys, brain, and skin, a mast cell disease, such as a mast cell activation disorder like mast cell activation syndrome (MCAS), may also be present.
Mast cell diseases can also lead to insufficient HNMT activity in these areas. Histamine breakdown in the central nervous system, i.e., in the brain, works exclusively via HNMT, but not via DAO. It is not surprising that neurological symptoms are in the foreground in an HNMT degradation disorder.
As already mentioned, a functional disorder of HNMT has no significant influence on the histamine breakdown of food, unless it concerns liberators. Histamine liberators cause a release of the body's own histamine. This can be due to the consumption of certain foods or due to stress and physical exertion. It is obvious that an HNMT degradation disorder leads to a chronically slightly elevated histamine level, especially if the mast cells release a lot of histamine.
In such a case, the histamine level would rise higher than with a normally functioning HNMT and remain at this level for a longer period of time. It is not surprising after these explanations that there are some sufferers of chronic histamine intolerance for whom even histamine-rich foods only cause symptoms after hours or even days, which often only completely subside days later. In contrast, in a DAO degradation disorder, acute symptoms appear within minutes after eating histamine-rich food and usually subside quickly.
Diagnostic possibilities for an HNMT degradation disorder
To determine the functionality of the enzyme DAO, both DAO activity in blood serum and plasma histamine levels are measured in diagnostics. To measure an HNMT degradation disorder, however, the methylhistamine concentration in urine is evaluated. However, it should be noted that methylhistamine levels also increase after consuming protein-rich foods.
Counteracting HNMT degradation disorder — is that possible?
Is there such a thing as HNMT tablets to counteract a histamine degradation disorder? In fact, there are antihistamines with the active ingredient dimetindene, which are supposed to stimulate HNMT and promote histamine breakdown. However, these do not combat the cause of the actual problem. Further measures that can be taken are the following:
- Avoid HNMT blockers: These include certain active ingredients in medications, such as diphenhydramine. Certain dietary supplements and luxury foods are also suspected of blocking HNMT. Since there is no study evidence, it must be individually tested here whether abstinence brings improvement.
- Elimination diet: strict avoidance of histamine, histamine liberators, and enzyme blockers
- Medication support in the presence of mast cell disease
- Consume HNMT-promoting nutrients
- Relieve and strengthen the liver
An investigation of HNMT inhibitors is particularly interesting, as it found that these block histamine breakdown. These include diphenhydramine, an H1 antihistamine. Furthermore, the same effect was found with
- Tacrine (Alzheimer's drug)
- Amodiaquine (malaria drug)
- and Metoprine.
Since HNMT is primarily active in the liver, normal liver function also plays an important role in histamine metabolism. Our MetaFit contains choline, which contributes to the maintenance of normal liver function. The formula is supplemented with vitamin C from acerola and selected bitter substances from milk thistle, dandelion root, and coriander. MetaFit is suitable for a low-histamine, low-fructose, gluten-free, and lactose-free diet. In addition, it is vegan and free of unnecessary additives.
Lieferzeit: 2-3 Tage
