Dr Joneja's Guides to Histamine Intolerance

A Beginner's Guide to Histamine Intolerance – read more about it here.
Buy the paperback from Amazon here; buy the e-book from Amazon here.

Histamine Intolerance: The Comprehensive Guide for Healthcare Professionals – read more about it here. Buy the ebook from Amazon here.

You can buy all of Dr Joneja's books here in the UK or here in the US.

Why is olive oil allowed on some, but prohibited on other histamine-restricted diets?


I figured out about 4 weeks ago that I am histamine intolerant. It has been very confusing with so many food lists out there, so I was glad to find yours, but I have some questions.

Is olive oil out? I’m assuming avocado oil is a no since avocados are out.  What only should I use? I can’t have dairy, so butter is out.

Dr Joneja says:

There are now numerous versions of a histamine-restricted diet available on the internet.  It is not surprising that people are becoming quite confused and do not know whom to believe.  The reason for many discrepancies is that the authors of the diet do not understand the science behind some of the directives.

Dietary restrictions are not all about the histamine content of the food as measured by analysing a sample in the laboratory. That merely tells us about that particular sample and the measurements depend on the methods used for analysis and on the origin of the sample being tested.  However, it does not tell us about how the body might respond to the food when it is consumed.  For example, a food may be entirely free from histamine, but contain a chemical that has the ability to release histamine within the body.  Benzoates, tartrazine, some other azo dyes, and sulphites have this ability.  Therefore, foods containing these chemicals are excluded on my histamine-restricted diet. 

Another aspect of histamine sensitivity must also be considered when formulating a histamine-restricted diet:  people with a deficiency in diamine oxidase (DAO) production will react differently from those who produce a normal level of the enzyme.  This has been entirely overlooked by many consultants in the field.  Olive oil is a very good example of this.  Although some sites recommend olive oil on a histamine-restricted diet, and even provide evidence that the oil promotes DAO production and therefore is beneficial for people with histamine intolerance, science shows us something very different.  Olive oil, or more accurately, the omega-9 fatty acid called oleic acid that it contains, will trigger the release of DAO, but it does so via the intermediate production of histamine.  That is fine for people with normal levels of DAO, which degrades the intermediate histamine and therefore does not boost histamine levels in the process.  But for people with DAO deficiency, the enzyme is unable to break down the intermediate histamine, and so the net result is an increase in their histamine levels.  For the latter, olive oil is definitely not safe. I am copying in below an article that I recently wrote on this topic that demonstrates this.

 A histamine restricted diet, like every other therapeutic diet, must be formulated for each individual according to their unique needs, which includes their physiology as well as life style.  No one size fits all, regardless of what the popular press might tell us.  That is the approach I have always taken in my practice and consider anything less to be detrimental to good dietary management of any condition.

In answer to your specific question:  canola oil, which contains a relatively good level of omega-3 fatty acid, will be the best choice for your particular needs.  Safflower and sunflower oil would be good secondary choices.

Thank you for your questions.  I hope you find this information helpful.

Why olive oil is allowed on some, but prohibited on other histamine-restricted diets.

Olive oil contains a long-chain fatty acid, called oleic acid.  It is an 18-carbon chain with a double bond at the omega-9 position, so is known as a monounsaturated omega-9 fatty acid or EFA (essential fatty acid).

When fats and oils enter the digestive tract, the body needs to absorb the fat.  One of the ways this is achieved is by the immediate production of histamine, followed closely by the production of diamine oxidase (DAO) to ensure that the histamine is not in excess and therefore likely to produce an adverse reaction.  For the information of those readers who are familiar with my “Health Professional’s Guide to Histamine Intolerance”, the process is mediated by the histamine receptor H4R, and therefore cannot be regulated with the use of antihistamines which block either H1R or H2R.  High caloric value fats, and especially long-chain fatty acids as in olive oil, are particularly efficient in triggering this system.  In most people with normal levels of DAO this works fairly well.

However, if for some reason, such as a genetically-determined deficiency in DAO, a person is not producing sufficient DAO to break down the histamine, excess histamine may result.  So such people are unlikely to tolerate olive oil.

So, reports indicating that olive oil increases DAO are correct.  But at the same time, olive oil does lead to an increase in histamine.  As in many cases of histamine intolerance (HIT), it all depends on a person’s degree of sensitivity, usually determined by their capacity to produce DAO.

Since my histamine-restricted diet directives are designed for people with HIT, I err on the side of caution and put olive, and other related oils, such as avocado, and certain other plant oils on my “do not consume” list.


Ji Y, Sakata Y, Li X, Zhang C, Yang Q, Xu M, Wollin A, Langhans W, Tso P. Lymphatic diamine oxidase secretion stimulated by fat absorption is linked with histamine release.
Am J Physiol Gastrointest Liver Physiol. 2013 Apr 15;304(8):G732-740

Selig WM, Patterson CE, Henry DP, Rhoades RA.  Role of histamine in acute oleic acid-induced lung injury. J Appl Physiol. 1986 Jul;61(1):233-239.

Wollin A, Navert H. Release of intestinal diamine oxidase by histamine in rats.
Can J Physiol Pharmacol. 1983 Apr;61(4):349-355.  

November 2018

December 2018

We posted a link to the article above on Facebook and got the following query:

Have you any research or comments on using copper surfaces/pots/utensils to inhibit histamine growth in food?

To which Dr Joneja replied:

As in all science, there is often a great deal of misunderstanding and misinterpretation as data reaches the general public.  Here is the basis for the copper/histamine connection that I was researching in my sabbatical year in Birmingham in 2003.

Diamine oxidase (DAO), the enzyme that breaks down excess histamine, is a copper-dependent enzyme, which means that its activity is dependent on copper as a co-factor.  Our bodies contain sufficient copper for the enzyme to work, so no need for supplemental copper.  However, as often happens, when such information becomes available, people in the nutrition industry will capitalize on the data and suggest  that supplementation will enhance the effect on the enzyme and  propose that consuming extra copper will help those with histamine excess.  Hence the idea that using copper pans etc will increase the copper in food cooked in them and boost the enzyme’s activity.

So your enquirer’s question underlines two misconceptions:  
That using copper utensils reduces the histamine content of food - which it does not! This is a great leap from enhancing the activity of DAO to reducing histamine in food completely independent of DAO.

And that copper in utensils will enhance the content of copper in the food, and lead to enhancement of DAO activity when the food is consumed, for which there is no evidence.

Amazing how misconceptions start and become embellished in the retelling isn’t it? I seem to have spent a great deal of time in this field debunking myths and misconceptions.  This is just the latest in a long string of such.

You can buy DAO supplements here in the UK or here in the US. You can buy all of Dr Joneja's books here in the UK or here in the US.

If you found this article interesting, you will find many more articles on anaphylaxis here, and reports of research into anaphylaxis here.
You can also find articles on peanut and tree-nut allergy here, cow's milk allergies here, egg allergy here, histamine intolerance hereand articles on a wide range of other allergic and intolerance reactions to a wide range of other foods here.


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