Dr Joneja's Guides to Histamine Intolerance

Dr Janice Joneja, a world expert on histamine intolerance, has published two books on 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.

What can cause histamine intolerance?
As part of our on-going histamine Q & A, Dr Janice Joneja was asked what could be causing a histamine intolerance.


I'm newly discovering the concept of histamine sensitivity and am truly hoping it provides the answers I've been seeking for decades.

Is there blood work or some other form of diagnosis I can revive to know exactly which form I have and thus which elimination route is best for me?

I recently received extensive blood work which provided some insights, but no firm direction.

Thank you for your ground-breaking work in this area .... which I suspect will help countless people achieve optimum health and vitality!

Dr Joneja says:

Thank you for your appreciation and support of my work.

The most important aspect of understanding histamine sensitivity or intolerance is to recognise that the symptoms of the condition are entirely due to an excessive amount of histamine in the body.  As I have discussed in many of my publications, it is like a bucket filling up with water.  When the contents overflow, symptoms are evident.  The point of overflow and appearance of symptoms is termed a person’s limit of tolerance.  This level is an individual characteristic.  People with low levels of the enzymes that break down excess histamine, mainly diamine oxidase (DAO) and to a lesser extent, histamine N-methyl transferase (HNMT), have a significantly lower threshold level of tolerance than the normal population.  However, people who produce normal levels of DAO can still experience symptoms of histamine excess if they exceed the capacity of their DAO to break down histamine fast enough to keep them below the level at which symptoms develop.

A variety of factors can lead to excess histamine, which I have discussed in my various publications - “Health Professional’s Guide to Food Allergies and Intolerances” Chapter 31, pages  291-304. (You can buy all of Dr Joneja's books here in the UK or here in the US.)

Depending on a person’s sensitivity to them, they may include:

  • Allergy to any allergen including air-borne pollens, dust, animal dander, mold spores, among others; injected insect stings and venom; ingested food and beverage ingredients, to name a few
  • Any inflammatory condition which may be chronic, or a result of infection, autoimmune processes or trauma
  • Mast cell activation disorders in which excessive numbers of mast cells are stimulated to release their stores of inflammatory mediators, that include large quantities of histamine
  • Hormone changes, especially at menarche and menopause in women, and lowering of testosterone levels in men
  • Micro-organisms in the bowel that produce the enzyme histidine decarboxylase that converts histidine in residual proteins into histamine that is absorbed into the body
  • Agents used in medical treatment or tests, such as radiographic dyes and some that may be used as part of anesthesia
  • Dietary ingredients containing high levels of histamine, often as a result of manufacturing processes, and foods and beverages that have the capacity to increase histamine release by a variety of mechanisms; the latter include artificial colours (tartrazine and other azo dyes), and preservatives such as benzoates and sulphites. See Dr Joneja’s article here.

Furthermore, DAO activity in histamine breakdown (catabolism) can be reduced by certain medications and other factors.  Consequently, contrary to many people’s hopes, it is not realistic to expect that a single test would accurately diagnose histamine sensitivity, or DAO activity, in any individual.

So, in answer to your query: in order to determine the best approach to the management of your histamine sensitivity you will first of all need to determine whether any of the conditions listed above is likely to be a source of your excess histamine, and take steps to address that.  Until the underlying cause is treated, excessive amounts of histamine will continue to be released into your body.  A histamine-restricted diet can only reduce histamine coming from outside the body (extrinsic sources), but will not reduce the amount from whatever process is triggering its release within (intrinsic histamine).  A histamine-restricted diet in this case will reduce the severity of the symptoms, but will not lead to complete remission.  I do not know exactly which tests you have undergone, nor their results, so am obviously unable to advise you as to the most likely cause in this case.

If all sources of excess histamine have been ruled out by appropriate tests, it would be a good idea for you to undertake a histamine-restricted diet.  Follow the directives of foods to avoid, and consume those allowed for a period of 2-4 weeks.  If you experience symptomatic relief you may assume that histamine sensitivity, possibly due to low DAO activity, is contributing to your condition and will be able to control your symptoms for the long term.  Detailed information about which foods are allowed and restricted on the diet can be found in my book, Dealing with Food Allergies  and the consumer factsheet associated with “The Health Professional’s Guide to Food Allergies and Intolerances”

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

January 2016

If you found this article interesting you can find a number of other articles on histamine intolerance both by Dr Joneja and others here, reports on histamine research here and a Q & A section on histamine with Dr Joneja here.

For many, many other articles on every type of food allergy and intolerance click here; for coeliac disease and other food related conditions, go here.

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Dr Janice Joneja, Ph.D., RDDr. Janice Joneja is a researcher, educator, author, and clinical counsellor with over thirty years of experience in the area of biochemical and immunological reactions involved in food allergy and intolerances. Dr. Joneja holds a Ph.D. in medical microbiology and immunology and was a registered dietitian (RD) – now retired. 

She has been a member of the faculty at several Canadian universities, starting her career as an Assistant Professor in the Department of Microbiology, Faculty of Science, and in the Faculty of Dentistry, at the University of British Columbia, Vancouver. Since 2001 Dr. Joneja has been a faculty member in the School of Biomedical and Molecular Sciences, at the University of Surrey, in England, teaching in the M.Sc. course in Nutritional Medicine.  For 12 years she was head of the Allergy Nutrition Program at the Vancouver Hospital and Health Sciences Centre.

Dr. Joneja is the author of six books and a dietetic practice manual on food allergy, a textbook on Irritable Bowel Syndrome, and several distance education courses. Her most recent books include “The Health Professional’s Guide to Food Allergies and Intolerances”, “Dealing with Food Allergies”, and “Dealing with Food Allergies in Babies and Children”.  Dr. Joneja’s work has been published in peer-reviewed scientific and medical journals, as well as in popular magazines.  She is a respected lecturer at universities, colleges and hospitals internationally, and regularly appears on television and radio call-in shows as an expert in her field.

Dr. Joneja is President of Vickerstaff Health Services, Inc., a practice that provides counselling for people suffering from all aspects of adverse reactions to food, and resources for the professionals and care-givers who support them.

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