Histamine is vital but, at the same time, it is a perverse substance. It is considered vital because there are many biological mechanisms that would not make sense without it. Thus, for example, it is capable of producing vasoconstriction or vasodilation, as required, and it can also increase an inflammatory focus so that immune cells can reach it.
Conversely, it can be a perverse substance if found in excessive amounts anywhere in the body. It can bind to various receptors and cause multiple symptoms. However, sometimes the process of histaminosis can be predicted. One example is that almost all patients get a swollen belly when they eat a certain food. This is a warning from the organism, saying that this is “poison” for it. Animals, such as dogs, are able to identify that something has not been good for them and do not eat it again, but humans are unable to do so, among other reasons because we mix so many foods in our meals that we cannot distinguish it well.
How to identify diseases caused by histamine?
These diseases can be classified both by the origin of the histamine and by the areas where it impacts or the symptoms it causes.
If we focus on the origin of histamine, pathologies can be exogenous or endogenous:
- Exogenous origin. They are caused by histamine contained in the diet, which has not been correctly deactivated in the digestive tract. Thus, it passes into the blood and then produces various symptoms, which is known as Enteral Histaminosis Syndrome (HE).
- Endogenous origin. Excess histamine from that accumulated in the person’s cells. Within this type there are several sections to consider, depending on the mechanism inducing the release. If the mechanism is mediated by a protein called lgE, it is an allergy and can be caused by pneumoallergens (mites, fungi, pollen), food proteins and/or drugs. Normally this condition has very characteristic symptoms. If the mechanism is not lgE it will be a process of non-allergic food histaminosis (NAFLD), which is the most frequent and responsible for the symptoms.
Dietary histaminosis: when the enzyme diamine oxidase does not deactivate histamine in food.
Diamine oxidase or DAO is an enzyme that we have in the digestive tract and is responsible for deactivating the histamine that we ingest along with food (histamine is in all foods and fermented foods). However, sometimes this is not the case and it reaches the blood, which can cause different symptoms that are summarized in the Enteral Histaminosis Syndrome. The body of a healthy person is able to deactivate histamine from food and not cause problems, but this does not happen when DAO does not work.
One of the causes for DAO not working is the consumption of drugs. There are many drugs that inhibit the action of diamine oxidase, causing histamine from food to pass into the blood. This can lead to chronic problems. For example, if a person diagnosed with Helicobacter Pylori is treated with antibiotics, symptoms flare up. The reason is that the antibiotic inhibits DAO and histamine in the diet. Afterwards, a diet as low as possible in histamine should be followed.
Drugs are harmful, although they are used to alleviate symptoms.
Drugs are a problem. Once the patient has been analyzed as a whole, assessing all the symptoms, the specialist in Clinical Analysis will consider whether it is a possible case of HANA or not. The fact that closed protocols are applied to a symptom can have positive points but also drawbacks, since the use of symptomatic medication must be the more restrictive the better, so as not to create DAO inhibition.
Before the patient suffers from HANA, the specialist should exclude drugs, as well as the foods that cause the most problems: dairy products, wheat and some meats.
Few physicians assess nutritional issues in the diagnosis of non-allergic food histaminosis.
Few specialists assess patients from the point of view of nutrition and assume its importance. However, with merely symptomatic medication, there is the possibility of an Enteral Histaminosis Syndrome due to a decrease in DAO.
Patients who have two or more symptoms characteristic of HANA can be diagnosed at any office visit. A single blood test, a clinical diagnosis and the trial of therapeutic diets based on the frequency of possible foods responsible for the symptoms would be sufficient.