The Lab Test For Histamine Intolerance

November 3, 2015  |  Blog, Histamine Intolerance

One of my current frustrations is that 23andMe™, and online report readers, are used to self-diagnose rather than get the lab test for histamine intolerance.


Here is a report from a popular online 23andMe™ report reader of the “DAO” snps from one of my clients.

HIT result 02

You could be forgiven for thinking that this person actually has a high probability of diamines oxidase (DAO) deficiency. But they don’t.

ImmunoPro Blood Test

Only problem is here is a blood test that proves that she does not have DAO deficiency.

HIT result 01



Which Test Is Right?

So what could have gone wrong? And whom should she believe?

Here is why the online report reader should be disregarded:

  • DAO on the report is not diamines oxidase. It is actually d-amino acid oxidase. They are not the same.
  • The current name for the DAO gene is AOC1. Its previous name was ABP.
  • Around seven AOC1 snps contribute to DAO deficiency whilst three AOC1 snps were even found to enhance DAO. Even so these SNPs did not provide a working model of histamine intolerance.
  • None of the report readers report on any of these 7 snps of AOC1.
  • 23andMe™ does collect the data for these 7 snps, meaning they can be mapped on the Livewello™ app, but 23andMe™ just shows the genetic possibility, not the actual expression of the gene.

Here is why the blood test is a better guide:

  • It is an accurate assessment of available DAO within the blood at the time of collection.
  • BUT DAO can change depending upon your diet (the higher in histamines the less circulating DAO). If you have DAO deficiency on your first test, it is worth retaking the test after implementation of a low histamine diet, to determine the DAO Deficit. This is considered the gold standard in DAO deficiency diagnosis.
  • BUT DAO deficiency can change over time, particularly with any gut damage, and
  • DAO deficiency is not the sole cause of histamine intolerance. It is just one of them.

The bottom line is if you suspect histamine intolerance then get tested. Its around A$150.

It will help to rule in or out DAO deficiency as the source of your histamine intolerance, and that will help to provide targeted solutions, to help you reduce your symptoms quicker.

Additional Resources

SciTech Laboratory in Germany runs all the tests but it now has distributors in most countries including:

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  • Elizabeth N. Baylor

    I found this link to get a Gene report for the AOC1 Gene in Livewello’s Gene Library. I wonder if there are more?

    • Yes I actually built that report. But it tells you nothing. So you have a mutation? What does it mean? It just means that you may or may not have dao deficiency. The test tells you if you do.

      • Elizabeth N. Baylor

        Oh okay I found the info helpful. But they do tell you that you need functional labs and a practitioner in addition to the gene test anyway.

        • Yes I am not against 23andMe. I am just against diagnosing on the basis of 23andMe and self-diagnosed or even worse seeing a genetic counsellor and on the basis of 23andMe alone have sold them a slew of supplements. If you get tested you can find the route cause.

  • Crabpaws

    Genetic tests indicate only a very slightly increased tendency toward an illness, not a diagnosis. Very few illnesses have been closely identified with any genetic patterns. The research on this is very much in its infancy and may never identify the causes of most diseases, which are multi-factorial and probably depend a great deal on environmental influences.

  • Katherine Arbuckle

    So what exactly is the lab test that I should request from my health practitioner in order to find out if I am histamine intolerant? Which test checks for DAO deficiency as well as the HNMT?

    • Hi Katherine thanks for asking there is no test that does both DAO and HNMT. I am reviewing these tests one by one so stay tuned.

      • Katherine Arbuckle

        Thanks, Alison. I look forward to the results of your review.

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  • adrian

    Well this says DAO gene is associated with histamine.

    PLoS One. 2012;7(11):e47571. doi: 10.1371/journal.pone.0047571. Epub 2012 Nov 12.

    The diamine oxidase gene is associated with hypersensitivity response to non-steroidal anti-inflammatory drugs.

    Agúndez JA1, Ayuso P, Cornejo-García JA, Blanca M, Torres MJ, Doña I, Salas M, Blanca-López N, Canto G, Rondon C, Campo P, Laguna JJ, Fernández J, Martínez C, García-Martín E.

    Author information


    anti-inflammatory drugs (NSAIDs) are the drugs most frequently involved
    in hypersensitivity drug reactions. Histamine is released in the
    allergic response to NSAIDs and is responsible for some of the clinical
    symptoms. The aim of this study is to analyze clinical association of
    functional polymorphisms in the genes coding for enzymes involved in
    histamine homeostasis with hypersensitivity response to NSAIDs. We
    studied a cohort of 442 unrelated Caucasian patients with
    hypersensitivity to NSAIDs. Patients who experienced three or more
    episodes with two or more different NSAIDs were included. If this
    requirement was not met diagnosis was established by challenge. A total
    of 414 healthy unrelated controls ethnically matched with patients and
    from the same geographic area were recruited. Analyses of the SNPs rs17740607, rs2073440, rs1801105, rs2052129, rs10156191, rs1049742 and rs1049793 in the HDC, HNMT and DAO genes were carried out by means of TaqMan assays. The detrimental DAO 16 Met allele (rs10156191),
    which causes decreased metabolic capacity, is overrepresented among
    patients with crossed-hypersensitivity to NSAIDs with an OR ?=?1.7 (95%
    CI ?=?1.3-2.1; Pc ?=?0.0003) with a gene-dose effect (P?=?0.0001). The
    association was replicated in two populations from different geographic
    areas (Pc ?=?0.008 and Pc ?=?0.004, respectively).


    The DAO polymorphism rs10156191
    which causes impaired metabolism of circulating histamine is associated
    with the clinical response in crossed-hypersensitivity to NSAIDs and
    could be used as a biomarker of response.s it is the same:

    • The DAO gene is associated with histamine but the DAO on 23and me is not the same gene. DAO on the report is not diamine oxidase. It is actually d-amino acid oxidase. They are not the same. It has also undergone various changes. Feel free to google on snpedia.

  • Where can I get the Advanced Intestinal Barrier Assessment 5150 test direct, without going through a practitioner?

  • HK1

    I just want to point out that a comprehensive review by 13 German doctors/researchers released in February 2017 at SpringerLink indicates that testing blood serum for DAO is unreliable. Here’s what the paper says about it: “According to current data, diagnosis based on the measurement of DAO enzyme activity in blood serum cannot be considered conclusive. Using DAO specific monoclonal antibodies, it was possible to detect DAO in various tissues, such as kidneys, intestine, and placenta—not, however, in blood serum, or at least not in relevant quantities. This finding casts conclusive doubt on the utility of serum analysis. Nevertheless, a recent study has once again proclaimed the reliability of determining DAO activity in blood serum. In stark contrast to earlier works, DAO values in that particular study’s limited control group were in the normal range.”

    • hi harlan. Thankyou I have read this paper and summarised it on this blog I believe. This post is out of date in terms of how I work and my thinking is constantly evolving based on research in this area and my own clinical practice.