Histamine is a chemical stored within our body and is produced from histidine (a natural amino acid), by the enzyme histidine decarboxylase – HDC. It is grouped with a class of neurotransmitters named – ”Small Molecule Neurotransmitter Substances,” alongside epinephrine, serotonin, and dopamine.
In 1910, English scientists Henry H. Dale and George Barger first isolated it from the plant fungus ergot.
In humans, the highest levels are found in the lung, skin, the mucous membrane of the gastrointestinal tract, and smaller amounts in the heart and the hypothalamus. Depending on what receptor it interacts with, and where it is found in the physical body, it can cause different reactions.
“Normal” blood levels for humans are 0.3 – 1.0 ng/mL, however, individual tolerance is variable. Some individuals will experience a reaction to ”normal levels,” due to the fact that they have a lower capacity to break it down in their digestive system.
Chemically, it works in the physical body by binding with special receptors (H1R, H2R, H3R and H4R) on protein molecules in different parts of the body. It increases the permeability of the capillaries to some proteins and white blood cells, to allow them to engage pathogens in the infected tissues.
Furthermore, it is a component of stomach acid, where it facilitates the breakdown of food by inducing a higher secretion of gastric acid by stimulating the H2-receptors of the parietal cells (also known as oxyntic cells) of the gastric mucosa. It acts as a neurotransmitter (a chemical that facilitates the transmission of impulses from one neural cell to a nearby neural cell) and communicates vital messages from your body to your brain.
When an allergen triggers the immune system in an attempt to protect the body, the mast cells (a type of white blood cells present in most tissues surrounding nerves and blood vessels) release histamines and other chemicals into the bloodstream as part of the inflammatory immune reaction.
In healthy individuals, the ingestion and production of histamines are balanced out by an enzyme named DAO – diamine oxidase. It is the principal enzyme for the metabolism of consumed histamine from foods. Another enzyme responsible for breaking down this chemical is called N-methyltransferase.
Moreover, different types of stress increase brain histamine, such as – loss of blood, dehydration, emotional stress, or severe infection.
Antihistamines prescription medications work by preventing the release of this chemical from certain cells (especially mast cells) thereby blocking the allergic reaction. However, these drugs have side effects, like – upset stomach, drowsiness, nervousness, difficulty urinating, dry nose, and dry mouth. In severe cases, sufferers may require treatment for hypotension or bronchospasm.
Low histamine foods and drinks:
Grains – corn, spelt, yeast-free rye bread, rice, rice crispbread, black rice bran, oat flakes, oats, oat bran, millet, puffed rice crackers, amaranth, and quinoa.
Fresh vegetables – cabbage, lettuce, watercress, pumpkin, rutabaga, beetroot, bell peppers, radish, onion, paprika, lamb’s lettuce, carrot, potato, yams, sweet potatoes, brussels sprouts, broccoli, rhubarb, zucchini, leek, kale, asparagus, sweet corn, turnip, and butternut squash.
Herbs and spices – moringa, holy basil, thyme, chamomile, turmeric, peppermint, tarragon, nettle, and ginger.
Fresh fruits – melon, cantaloupe, pomegranate, peaches, cranberries, mangosteens, blueberry, mango, litchi, red currants, khaki, cherries, apricot, apples, capers, and plums.
Plant based milk – rice milk, coconut milk, almond milk, hemp milk, oat milk, and potato milk.
DAO – Diamine oxidase blockers
- black tea
- green tea
- energy and sports drinks
- mate tea
- certain prescription medications contribute to blocking diamine oxidase and preventing production.
High histamine foods and drinks list
There are numerous foods which naturally contain high levels of this chemical. This can be problematic for individuals unable to break down histamine. Foods high in this chemical include:
- vinegar products (vinegar and mustard);
- pickled and fermented vegetables;
- aged foods (in general, the longer a food is left to mature or stored, the higher its content in this chemical will be);
- alcohol (particularly beer and red wine);
- chocolates and other cocoa-based products;
- energy drinks and colas;
- spices, like – chili powder, cinnamon, and anise;
- eggs, particularly egg whites;
- processed and smoked meat products, such as – ham, salami, sausages, and bacon;
- nuts, especially walnuts and cashews;
- legumes – soybeans (and soy products, like tofu), chickpeas, peanuts, lentils, red kidney beans;
- canned or fresh tuna, mackerel, sardines, herring, salmon, and processed fish products, such as – dried pickled fish or fish pastes;
- tomato and tomato products, like ketchup. Red tomatoes contain higher amounts of this chemical than orange or yellow;
- yeast containing foods, like – cakes and bread. You should choose bread and grain products produced with unbleached flour;
- cow’s milk and the majority of dairy products, like – cheeses (parmesan cheese, blue cheeses, old gouda, camembert, cheddar), yogurt, kefir, buttermilk, and sour cream;
- dried fruits – cranberries, prunes, figs, dates, currants, and raisins;
- fruits – bananas, strawberries, kiwi, papayas, pineapple, grapefruits, tangerines, red prunes, raspberries. You should avoid consuming overripe fruits because the histamine levels rise as these foods ripen;
- artificial preservatives and colors – sulfites, benzoates, tartrazine benzoates, glutamate (MSG), BHT and BHA;
- supplements – folic acid (the synthetic form of vitamin B9, better known as folate) increases the levels of this chemical, thus, you should avoid it.
Symptoms of histamine intolerance
This type of intolerance affects at minimum 1 percent of the population. Nevertheless, the majority of people with this type of intolerance go undiagnosed (considering the diversity of symptoms), therefore the true prevalence is definitely much higher. The symptoms and signs of an intolerance may include:
- confusion, fatigue, or irritability;
- loss of consciousness or blacking out for a few seconds unexplained by other known disorders;
- migraines or headaches;
- a runny nose and nasal congestion;
- swollen tongue, lips, or face;
- burning sensation in the bladder, identical to a bladder infection;
- itchy and red hives, rashes, or eczema;
- aphthous ulcers in the mouth and other types of infections in the mouth;
- reflux, nausea, abdominal pain, vomiting, or diarrhea;
- accelerated heart rate, or arrhythmia;
- low blood pressure;
- temperature dysregulation;
- sinus pressure, that may lead to facial pain;
- experience inner tension;
- premenstrual cramping;
- itchy eyes;
- trouble getting to sleep or light sleep.