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Can you spot Histamine Intolerance?

Histamine is an inflammatory mediator.  When a release of histamine is triggered it helps the immune system respond to threats (e.g. infections, allergies (which are essentially the body’s “imagined” threats)).  Capillaries are dilated to increase circulation and become more permeable to help white blood cells get to where they are needed.  This is helpful when it’s needed and assuming the process is well-managed within the body.

As with many things in the body (e.g. cholesterol, estrogen, fibrinogen, cortisol), too much of a good, normal, natural thing can become debilitating or even life-threatening.  Histamine intolerance is about the body becoming overloaded, where the amount of histamine present outweighs our ability to break it down (detoxify it).  Histamine comes from many sources.  Externally, we primarily get it from our foods.  Internally, we produce it in response to immune threats (as above), and some of the microbes in our gut also produce it as part of their normal metabolism.  In a healthy, balanced body, an enzyme in the GI tract (DAO, diamine oxidase) handles the histamine in our food.  Internal to the body, another enzyme system handles intracellular histamine (histamine N-methyltransferase  or HNMT).  Of course, nutrition is key here too, as both of these enzyme systems require B vitamins and minerals as cofactors.  And methylation (that pesky SNP issue again!) is also required to reduce intracellular histamine.

Unfortunately there is no single labwork marker or panel that can readily identify histamine intolerance.  Single, one-time measurements of histamine in the blood may be elevated due to specific triggers, but that doesn’t mean a person has an imbalance on an ongoing basis.  To be a helpful marker, histamine needs to be assessed several times to establish a trend.  There are many more advanced, functional testing options that can be helpful (e.g. stool test, lipid peroxides – to assess oxidative stress which can come from sustained, high histamine).  But you will find some clues in conventional labwork too, such as looking at the percentages of eosinophils and basophils in a Complete Blood Count.  Both of these WBCs secrete histamine.  In a healthy, happy, relaxed immune system, eosinophils are usually very low (<3% of WBCs) and basophils will be zero (or nearly zero).  Basophils are particularly strong secretors of histamine, so that’s a strong clue.  Many clients can also take a look at their total IgE antibody level in the blood, an indication of the body’s immune defenses being armed to secrete histamine.  Again, histamine levels can be high (creating the intolerance) due to strong sensitivity (high release) and/or poor detoxification ability (where it builds up over time).   Suboptimal Vitamin D and zinc (ideally measured through RBC Zinc) can also contribute to immune system dysregulation.

The easiest way to help a client to determine if they struggle with histamine intolerance is to do an experiment.  Help them to implement a low-histamine diet for a full two weeks and also support them with DAO supplements with meals.  If histamine is a challenge, they should experience significant relief.  My experience is that clients really want to be able to explore and assess their own challenges, so this type of empowered experiment is well-received, especially with your well-worded educational introduction (smile).

Foods high in histamine include dairy foods (especially cheese!), processed lunch meats, beer and wine (especially red wine), foods made with yeast (e.g. bread), all fermented/cultured foods, vinegars, anchovies, avocado, and canned fish (e.g. sardines).   But you might be surprised to learn that there are foods which promote histamine release without having high levels themselves e.g. chocolate, eggs, bananas.   Diets very high in protein can also be part of the problem, as the amino acid histidine is converted to histamine in the body.  A low-histamine diet can be a challenge, but remember that a client doesn’t have to implement it 100.0% in order to have a valid elimination trial and learn how their unique body responds.  There are some excellent resources available online to guide your clients (e.g. )

Supplements that can help include

  • Quercetin (a natural anti-histamine I wrote about in a prior clinical post).  Unlike typical A/H drugs, quercetin’s “side effects” are positive and helpful for gut-healing.
  • High-quality B-complex (critical for methylation to break down excess histamine internal to our tissues; be sure to choose one with active, methyl forms of B12 and Folate (B9) in particular e.g. Thorne’s “Basic B”)
  • Vitamin D3 and Zinc (very helpful labwork – to ensure they are optimal)
  • Diamine Oxidase digestive enzymes (to supplement what their body may not be making on its own)
  • A certain probiotic specifically with Lactobacilus Rhamnosus or Plantarum and good amounts of Bifidobacteria (Other forms of Lactobacilus can promote more histamine, especially if they are overgrown.  A probiotic I can recommend in cases like this is Metagenics UltraFlora Intensive Care.

These ideas can help to bring your client some substantial relief (and commitment to their work with you) while you help them to get to the root cause of their challenges.  Sometimes our clients have histamine intolerance simply because of genetics such as impaired methylation or impaired production of DAO or HNMT.  Supplements can be an easy way to overcome the detriment of genetics.  However, most people struggle with histamine intolerance between of a basket of interconnected imbalance in the body that you can in time help them to resolve.  Common contributors include low adrenal function (specifically low cortisol which typically promotes more Th2 hyper-reactivity to external threats), microbial imbalance/overgrowth in the gut (aka dysbiosis), too much overall protein intake, insufficient levels of key immune system nutrients (e.g. Vitamin D, Zinc, Copper, B vitamins), toxic environment/burden, chronic stress or lack of sleep, and (yes, believe it or not!) chronic, long-term use of antihistamine drugs (which over-ride the body’s natural regulatory systems and create more sensitivity).

Get comfortable catching and exploring Histamine Intolerance.  When you do, you will enjoy some extremely grateful clients, who have often struggled for many years in a medical system that has a hard time acknowledging (much less addressing) this particular dynamic.

If you’re passionate about this topic and want to do a deeper dive (especially if you want to learn more about relevant labwork), I highly recommend Dr. Ben Lynch’s article here.

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14 Questions for “Can you spot Histamine Intolerance?”

  1. 6

    I have a client that I’ve been working with since January 2020. We have been supporting gut healing, stress management and cleaning up her diet. Initially her eosinophils were >5.4% and with her last labs they decreased to >4.1% (which is still elevated), but better. My question, is this a sign of gut healing and possibly less of a histamine response by removal of gluten, dairy and processed foods? Thank you.

    • 6.1
      SAFM Team says:

      Unfortunately, there is no single labwork marker or panel that can readily identify histamine intolerance, or verify the efficacy of your healing plan. Also, we are also not able to provide targeted support for client cases in these forums as the full picture of all the lab markers and discussion of all symptoms would be required. That being said, the decrease in the eosinophil markers that you describe could potentially speak to the dietary improvements and the lessening of the histamine issues, or it is reflecting a shift for other reasons, such as an allergen decrease in the environment or a general change in the immune system activation due to the dietary changes. If you would like to explore this in more detail, here is a research article:

  2. 5
    Jane Roodenburg says:

    I have a patient who I believe has histamine intolerance. She is also allergic to apples and several other common fruits. Do you think quercetin would be safe for her?

    • 5.1
      SAFM Team says:

      Quercetin is a bioflavonoid that can be found in a variety of fruits and vegetables. Having and ‘allergy to apples’ may mean many different things and yes it could mean that querceitin may be an issue, but it could also be perfectly fine and helpful. Thus, unless you have specific information what part of the apple causes allergy, you may want to try a very low-n-slow introduction of quercetin. Here’s an article that may be of interest to you:

  3. 4
    Cynthia Newton says:

    Hi Tracy! You said that in a happy, relaxed immune system, basophils will be zero (or nearly zero). On this basis, would you consider 0.7% to be high? Eosinophils are 0.5%.

    Thank you! Cindy

  4. 3
    Denise Smith says:

    Tracy can you please link the post about quercetin? Thank you

  5. 2
    Denise Smith says:

    Can quercetin be taken instead of Benadryl? or both are needed in case of hives and itchiness? I’m referring to an almost 12 year old boy
    thank you

  6. 1
    Sharon Lees says:

    I am not familiar with diamine oxidase…but would like to use this combo with my client….brand dosage and timing of dosage would be most helpful….thanks in advance!

    • 1.1
      SAFM says:

      Unfortunately this is quite difficult to obtain at the moment due to import regulation snafus in getting the raw materials out of Europe and into the US. I usually recommend Xymogen or Seeking Health, but both are out of stock and backordered with no ETA at the moment. I held back on answering your question earlier in hopes of identifying another source for you but with no luck. In the interim, I recommend using a good natural herbal blend that includes quercetin and stinging nettle such as Orthomolecular’s “Natural D-Hist”. Note that glandular digestive enzymes (vs. yeast-derived) will also offer some low-level increment of these enzymes too e.g. Metagenics Azeo Pangen.

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