
Histamine intolerance may be difficult to diagnose because it can resemble seasonal or food allergies, which presents with the following signs and symptoms:
- Watery eyes
- Sneezing
- A congested, runny, or itchy nose
- Fatigue
- Headaches and migraines
- Hives and itchy skin
- Digestive issues (such as diarrhea, bloating, constipation, or irritable bowel syndrome-like symptoms)
- Irregular menstruation
- Unexplained anxiety
- Trouble breathing
Histamine intolerance could also manifest through flu-like or even food poisoning symptoms, such as heartburn, nausea, or hot flashes.
Histamine intolerance is a complicated condition that can be confused with a variety of other conditions, so it is critical to understand the exact cause to implement proper treatment strategies. Seek professional help to diagnose and treat the condition, and do not guess or attempt to treat yourself.
Diagnosing a histamine intolerance
If you have histamine intolerance, you may have these symptoms regularly or after eating certain foods. Because this intolerance can cause a variety of allergic reactions, a diagnosis based solely on symptoms is impossible.
- Usually, diagnosis of histamine intolerance is made through a process of ruling out other possible health conditions.
- A doctor would first test for allergies and possible food intolerances.
- If the test does not reveal a specific allergy or sensitivity, the doctor can begin testing for histamine intolerance.
- Because histamine intolerance is caused by a lack of specific enzymes in the body that metabolize histamine (diamine oxidase), the doctor can measure diamine oxidase and histamine levels before and after a low-histamine diet.
Two enzymes responsible for histamine breakdown
- Diamine oxidase enzyme: Breaks down external histamine in the gut (histamine release from food). It is primarily produced in the small intestine, ascending colon, placenta, and kidneys.
- Histamine N-methyltransferase enzyme: Breaks down histamine levels produced internally in the intracellular space (in between the cells). It is found primarily in the kidneys, liver, spleen, colon, spinal cord, prostate, ovary, and bronchi.
Impairment in the diamine oxidase enzyme appears to be a more significant contributor to histamine intolerance than impairment in the histamine N-methyltransferase enzyme.
How common is histamine intolerance?
Histamine intolerance affects approximately three percent of the population, with women over the age of 40 constituting approximately 80 percent of those affected.
There is no single diagnostic tool that can confirm a diagnosis, but an elimination diet is a simplest and most convenient way to find out if you have such an intolerance.
What is histamine intolerance?
Most people can tolerate the amount of histamine found in food because their bodies produce enough diamine oxidase. These enzymes break down and eliminate the compound quickly.
People suffering from histamine intolerance are likely to have low levels of histamine-clearing enzymes, allowing histamine levels to build up in their blood plasma and disrupt bodily functions. So, the problem arises when the body cannot get rid of the histamine.
While histamine intolerance is not a true food intolerance and thus is not usually considered life-threatening, the symptoms can be quite severe, leading many people to the emergency room.
Some of the factors that may contribute to the development of histamine intolerance include:
- Excessive consumption of histamine-rich foods (such as aged cheeses, alcohol, fermented foods like sauerkraut, cocoa products, yogurt, eggplants, tomatoes, spinach, and green tea)
- Foods that increase histamine production (e.g. alcohol, citrus fruits, bananas, tomatoes, chocolate, etc.)
- Consumption of foods that inhibit the breakdown of histamine (e.g. alcohol, green tea, black tea, and energy drinks)
- Medications that prevent histamine breakdown (such as some antibiotics, pain medications, and antidepressants)
- The presence of the wrong bacteria in the digestive tract, resulting in increased histamine production
- Certain nutritional deficiencies (e.g. vitamin B6 or zinc), some gastrointestinal conditions, prolonged stress, and liver dysfunction can make you more susceptible to histamine intolerance
What are the treatment strategies for histamine intolerance?
If you suffer from histamine intolerance, you can benefit from the following treatment options:
- Foods high in histamine should be avoided; stick to a low-histamine diet instead
- Avoiding histamine-producing substances
- Medication that inhibits diamine oxidase or histamine N-methyltransferase enzymes should be avoided after consulting a doctor
- Supplementation of the diamine oxidase enzyme with meals containing histamine, and the use of antihistamines or natural substances that aid in histamine breakdown
Because complete avoidance of histamine is not possible for most people, a combination of these strategies could be most effective.

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WebMD. Foods High in Histamine. https://www.webmd.com/diet/foods-high-in-histamine#1
Comas-Basté O, Sánchez-Pérez S, Veciana-Nogués MT, Latorre-Moratalla M, Vidal-Carou MDC. Histamine Intolerance: The Current State of the Art. Biomolecules. 2020;10(8):1181. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463562/
Peltz S. Histamine Intolerance. Spring 2018 https://www.polohealth.com/about/media/eco-parent/histamine-intolerance.pdf
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