Dietary Histamine Intolerance

Updated: May 2019

Histamine is a normal and important chemical in the immune system. However, excess blood levels can lead to symptoms. Histamine intolerance is a theory that dietary histamine increases blood histamine and allergy-like symptoms in susceptible individuals. A low histamine diet and diamine oxidase supplements may reduce symptoms.

Histamine Toxicity

Histamine toxicity is a type of food poisoning. As food spoils, the bacteria produce histamine and related compounds.  The most common food associated with histamine toxicity outbreaks is scombroid species fish, such as tuna (therefore, histamine toxicity used to be called scombroid poisoning). The dietary histamine is absorbed and circulates through the blood leading to allergy symptoms (see table below). With histamine toxicity, everyone that eats the histamine rich food develops symptoms.

Dietary Histamine Intolerance Theory

Histamine intolerance is a theory that some people are more likely to absorb histamine from food. They can experience histamine toxicity with a dietary histamine intake that most people tolerate.  Typical symptoms include:

Area AffectedExample Symptoms
Facial areaNasal congestion and runny nose (rhinorrhea), itchy watery eyes, sinus congestion
LungsRespiratory tightness and difficulty breathing (asthma)
Skin Hives (urticaria), swelling (angioedema), eczema, flushing, itching, etc.
CardiovascularBlood pressure irregularities, light headedness, increased heart rate (tachycardia)
GastrointestinalVomiting, diarrhea, pain, reflux, etc.
OtherHeadache, menstrual difficulties, brain fog, anxiety, etc. (very little is known about the connection between these other symptoms and histamine)

Histamine intolerance is more likely if you experience several symptoms, especially digestive. If you experience one or two symptoms only, you probably don’t have histamine intolerance.

There are two overlapping parts to this theory:

  1. Low levels of diamine oxidase (DAO) enzyme: histamine in food is broken down in the digestive system by the diamine oxidase enzyme. If DAO is not working properly, you are more likely to absorb dietary histamine. Read Diamine Oxidase Enzyme (DAO) for more details.
  2. Histamine releasing foods: Certain foods (such as egg white and strawberries) are said to trigger cells in the digestive system to release histamine. The histamine is absorbed into the body (especially with low levels of DAO).

If you are susceptible as described above, a diet low in histamine and histamine releasing foods and diamine oxidase enzyme supplements will improve your symptoms.

Very Little Research

A group of German physicians first proposed the histamine intolerance theory in the 1970s.  There were a few initial studies, but there has not been much research since. Dr. Janice Joneja (Immunology Ph.D. and Canadian dietitian) was one of the first health care professionals to translate this information and create English diet guidelines. I completed a Master of Science degree at the University of British Columbia (Dr. Joneja was one of my supervisors) in the mid-1990s researching the Benefit of a Histamine Reducing Diet in Chronic Urticaria and Angioedema. In summary, around 20% of the low-histamine diet subjects had substantial symptom improvement, which is what we expected.  Diet is one of many possible contributing factors to chronic urticaria (hives), so we did not expect everyone to improve. There have been a few studies investigating the low histamine diet since this time, but they have not used a strong study design.

Educated Guess

Since there is very little research, most histamine intolerance information is opinion or speculation. For example, there is no research to support the concept of histamine-releasing foods. This theory is a possible explanation for why some people experience allergy-like symptoms with specific foods, even though they don’t have a true allergy to the food. The theory was repeated through the years, and at some point, was assumed to be fact.  As awareness of this concept spread on the internet, those suffering from symptoms started adding their problematic foods to the lists. Restricted food lists grew longer and longer. In summary, the lists are anecdotal internet reports, not objective scientific information.

The low histamine diet is an educated guess, not a definitive diet. “Foods that have been reported to increase histamine-like symptoms” would be a more appropriate name for these lists.

No Accepted Diagnostic Tests

Unvalidated laboratory tests measuring blood histamine or diamine oxidase enzyme are available, but the clinical relevance is questionable. Read Diamine Oxidase Enzyme (DAO) for more details.

Histamine intolerance is a popular diagnosis right now. Many practitioners are giving people with hard to diagnose and treat “allergy-like” symptoms this diagnosis. However, dietary histamine intolerance is a self-diagnosis based on symptom improvement with a low histamine diet and/or diamine oxidase (DAO) supplementation. It is important to systematically trial these treatments and only continue if they make a difference.  I’ve talked with several clients that have been diagnosed with histamine intolerance (without objective evidence that a low histamine diet or DAO supplements are beneficial) and the client just assumes that they need to follow a modified diet.

Many Possible Symptoms Causes

If you have typical symptoms (see list above), it is natural to assume you have histamine intolerance and need to follow a low histamine diet. However, blood histamine can be high for many reasons (e.g., seasonal allergy, stress, hormones, etc.). Diet may or may not be a factor.

Some practitioners claim that a low histamine diet will lower total body histamine. This theory may be true for individuals with dietary histamine intolerance (e.g., low DAO activity). However, excess histamine from a different source (e.g., seasonal allergies), will not improve with a low histamine diet.

If a low histamine diet and/or diamine oxidase supplements have not improved your symptoms, you probably don’t have dietary histamine intolerance.

Overlap with Mast Cell Activation

Histamine intolerance and mast cell activation disease may overlap for some patients. Histamine releasing foods is one part of the histamine intolerance theory. In other words, certain foods are claimed to cause a release of histamine from cells in the digestive system. Histamine comes from mast cells, so this would be a form of mast cell activation.

For more information:  Comparing Allergy, HIT and MCAD

Low Histamine Diet Trial

Even though there is very little research to support the theory, many people have reported benefit from a low histamine diet. The good news is that symptoms will improve quickly. A three-week trial is long enough to know if you will benefit. Further details:  The Practical Guide to the Low Histamine Diet.

8 comments on “Dietary Histamine Intolerance
  1. Kimberly Sivage says:

    I have found significant relief in relation to my symptoms from a low histamine diet. I am in the United States and currently a low histamine diet is not well known here. I was wondering if you were able to provide any information in regard to dietitian programs In which the low histamine diet is the foundation in the curriculum. I am currently in my last year of my MSW program. When I began my practice I would like to be able to help my clients here not only mentally but physically as well, so I intend to be able to incorporate a low histamine diet as part of the healing regimen. I appreciate Your time. Have a blessed day.


    Kimberly Sivage

    • Wendy says:

      I’m not aware of any dietitian curriculum programs that include the low histamine diet.

      Be careful that you don’t “over-recommend” the low histamine diet. When you have personally found benefit from a treatment, it is tempting to make this recommendation more often than is warranted.

      Good luck with the rest of your studies!

  2. Francois says:

    Thanks for the article and information relating to Histamine intolerances and DAO. I have symptoms that could lead me to the path of Histamine intolerances (or Mast Cell) but the strange thing is, no matter of the diet or strick the food restriction is, I have symptoms re-occurring every 6 days (shorter if the diet is not followed). This is even happening while taking 40mg of anti-histamine. I have read that Quercetine and DAO supplements could be helpful. I am from Canada and not sure where to procure DAO supplements as a trial in addition to Quercetin and the low histamine diet. Suggestions? This has been a fight for over 5 years so any bits of advice would be greatly appreciated.

    • Wendy says:

      It’s interesting that your symptoms are occurring every 6 days. I wish that I have an explanation for you! To my knowledge, there is not a DAO supplier in Canada. It can be ordered through, but it is more expensive than ordering it through and paying the exchange and shipping charges (about an extra $20 to Canada).

  3. Sarah B says:

    Is turmeric good for histamine intolerance?

    • Wendy says:

      Many clients find supplements helpful, but it is very individual. It’s a long process, but you need to figure out what works for you. Rather than haphazardly trying different supplements, experiment with them systematically. For more information on this topic, please read – Systematic Experimentation (a summary article from my client modules).

  4. Jackie Morris says:

    Thanks for writing these articles. Natural factors quercetin bothers me. Is there a type that is lower in histamine?

    • Wendy says:

      Supplements like quercetin have not be tested for histamine, but it is unlikely that it contains histamine (histamine forms when bacteria grows in food – see Histamine in Food). There is probably a different reason that this supplement bothers you (i.e., it is probably not related to histamine).

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