Salicylate intolerance – Q and A with Dr Janice Joneja

May 2018


I am 28, and have been suffering from an allergy to aspirin and salicylates since I was about six. I keep a very low salicylate diet (which is very effective) but when I eat the wrong foods my reaction includes a red rash, itching, swelling fingers and swelling of the face, tongue and lips. I also get headaches and stomach aches and have to limit the cosmetics I use that contain salicylates or benzoates.

As a child, I was taken into hospital multiple times with anaphylactic shock. I was diagnosed with a salicylate allergy, and carried eppipens. I now take antihistamines regularly and sometimes need to take steroids to avoid adverse reactions.

I have seen multiple specialists, doctors and nutritionists. I was very concerned when I saw your advice. You say a salicylate allergy doesn’t exist. You advise people to give their children aspirin as a test, without ever having met them and without a real consultation.

My doctors told me that it was too dangerous for me to even take aspirin as a test as they feared it may result in anaphylactic shock and possible death.Do you really think it is appropriate to give this advice online, when you could be putting lives at risk? If I had been given this advice, and followed it, I could be dead. There is such a thing as a salicylate intolerance AND there is a salicylate allergy. How can you justify making the generalisation that all problems with salicylates, aspirin and associated substances are an intolerance and can never ever be an allergy?

Dr Joneja replies:

The answer is that salicylates are not allergens.  Allergens are proteins that trigger an immunological response with the production of antibodies.  Salicylic acid is an inorganic compound.  It does not trigger a response of the immune system, and therefore cannot induce an anaphylactic reaction.

The intolerance caused by a salicylate is due to its inhibition of the cyclo-oxygenase pathway from arachidonic acid which generates the prostaglandins.  The latter have many actions in the body, especially the control of smooth muscle contraction and relaxation. Prostaglandins are also responsible for the pain response in many disorders.  That is why acetyl salicylic acid (ASA or aspirin ) is used in the management of pain.  I have discussed this in many of my publications.

Without doubt a person, especially an asthmatic, can be very intolerant to salicylates.  This is because the inhibition of the cyclo-oxygenase pathway leads to an increase in the production of leukotrienes via the lipoxygenase pathway from arachidonic acid.  Leukotrienes are largely responsible for the bronchospasm of asthma.  Asthma certainly can be life-threatening.  But it is not due to an allergy, and is not anaphylaxis.

The symptoms reported can be due to a number of adverse reactions to food ingredients other than salicylates.  Furthermore, it would be difficult for a traditional allergist to be specific about a reaction to salicylate since there is no definitive test for salicylate sensitivity.  The symptoms she reports are typical of histamine sensitivity, which as we know, can be caused by many underlying triggers.  I would look more closely at those if I were managing her problems.

February 2015

We have two questions about salicylate sensitivity, which I will answer together.

Question A.

I have a 7 year old boy and suspect he may have a salicylate intolerance.
My impression is that he wets his bed when he has foods that are high in salicylate (Otherwise he doesn’t).  I believe he also seems more tired and occasionally on these days also acts “too silly” (not himself).
My questions are:
Is there any test for salicylate intolerance?  If so, do you know of anyone in London who does such a test?

If someone does have salicylate intolerance, is it necessary to avoid all foods high in salicylate or is a little bit OK?

Is there anything that can be done (such as addressing nutritional deficiencies, etc.) which can reduce or eliminate salicylate intolerance?
My son is on a gluten, dairy, soy free diet.  He does also not eat beef or lamb.  He has an older brother who was diagnosed as being on the autism spectrum many years ago.  I used to suspect he was sensitive to salicylates as well, but this seems to have gone away over the years as he improved. 

Question B
Hi, I'm salicylate intolerant big time...have been for 10yrs.
I'm learning about the importance of inflammation in relation to salicylate and other allergies/diseases etc and trying to find out about fish oils and/or the best alternative for reducing systemic inflammation.
Currently I take flax seed oil and a vit E cap daily.
Do you have any other recommendations?


Dr Joneja says:

The most important feature of these questions relates to the diagnosis of “salicylate intolerance”:  how was the salicylate sensitivity diagnosed, and by whom?

So often I am approached by patients who have surfed the internet and read numerous articles in popular magazines trying to find an answer to their various symptoms.  Salicylate intolerance, or sensitivity, is popular as a choice because the symptoms reported to be a result of the condition are so diverse and the foods responsible so numerous that it would be difficult to deny that the seeker has found the solution to their problem.  However, on looking at this more closely, salicylate intolerance is not so clear-cut, and is often an inaccurate diagnosis.

The only form of salicylate definitively demonstrated to trigger an adverse response is acetylsalicylic acid (ASA) known as aspirin. The usual dose in a regular aspirin is 325 mg; in extra-strength or arthritis pain relief aspirins, the dose is 600 to 650 mg of acetylsalicylic acid; and in a low dose or children’s aspirin, it is 81 mg.  This dose far exceeds the usual daily dose of salicylate in a normal diet, which is estimated to be 10 to 200 mg. Therefore, a fairly good way of determining if a person is salicylate sensitive is to monitor their response to aspirin.  If the symptoms develop after taking the aspirin, we then suspect that salicylates are contributing to the patient’s symptoms and initiate a salicylate restricted diet.  If, however, (which is so frequently the case in my experience) the person does not react adversely to the aspirin, we need to look elsewhere for the source of their problem. Furthermore, although a diagnosed sensitivity to aspirin is sometimes taken as a sign of possible salicylate sensitivity, because the levels of salicylic acid in aspirin and foods are so different, it is not valid to assume that an aspirin-sensitive person requires a salicylate-restricted diet.

Let us look at this more closely:
Salicylates, but not acetylsalicylic acid occur naturally in many foods. Research studies have not yet proven that food sources of salicylates cause adverse reactions even in persons sensitive to acetylsalicylic acid, but they are suspected.  Up to 25% of persons sensitive to acetylsalicylic acid also react adversely to the azo dye tartrazine. Sensitivity to acetylsalicylic acid has also been linked to sensitivities to benzoates and sulphites. The symptoms that develop from sensitivity to benzoates, azo dyes, and sulphites are often indistinguishable from those resulting from salicylate intolerance, because the mechanism of action of these substances is quite similar. Frequently, salicylate sensitivity has been blamed when the sensitivity is actually to one or more of these other food components. Since a low-salicylate diet is so restrictive and may pose unnecessary nutritional risk, it is often a worthwhile exercise to restrict benzoates, azo dyes, and sulfites (predominantly foods with artificial food additives) for a time-limited trial before complete salicylate avoidance is attempted.

Although the level of salicylic acid may be the determining factor in salicylate sensitivity, absorption may also play a role in the amount of salicylate available. In a medication, ASA is in the “free form”—that is, it is not linked to another compound and is immediately available for action within the body. When the salicylate is in a food, it is complexed with many other compounds, so it will not become active until released in its free form, which will take a certain length of time and will reduce the body’s immediate response to the chemical.

There are no laboratory tests available for diagnosing salicylate intolerance. A clear medical history, aspirin sensitivity, and analysis of a food and symptom record that indicates symptom development following intake of salicylate-rich foods are the best indicators that a trial of elimination and challenge of salicylates would be worthwhile

Salicylates are a natural component of a wide range of food plants. It would be extremely difficult, if not impossible, to formulate a nutritionally adequate diet by avoiding all foods that contain salicylate.  Several researchers have developed tables to indicate the level of salicylate in foods. However, the reported levels are not entirely consistent between data banks, because the level of salicylate in a food will vary according to plant variety, conditions in the growing environment, and methods of analysis in the laboratory. Furthermore, the level of salicylate detected in the body (by analysis of a research subject’s serum) varies, probably depending on individual absorption patterns and metabolism of salicylate within the body. There is still a great deal to learn before we can diagnose and manage either aspirin or salicylate intolerance effectively.

A salicylate-restricted diet removes those foods with a “high” level of salicylate, although in practice there is no research to indicate what “high” and “low” levels may be; these will depend on the person’s individual limit of tolerance (the level above which symptoms develop). In any case, because so many foods are eliminated the diet should not be followed for longer than 4 weeks initially. After this time, sequential incremental dose challenge of salicylate-rich foods should be undertaken to confirm salicylate intolerance.

In practice I have found that the majority of patients who consult me for their putative “salicylate intolerance” respond extremely well to a histamine-restricted diet.  The symptoms are similar in each “intolerance”, and the histamine-restricted diet removes the compounds that have a similar mode of action as salicylates, namely, tartrazine, benzoates and sulphites (see above) without eliminating the long lists of foods recommended for the salicylate restricted diet.

More information in chapter 26 “Salicylate Intolerance” in my recent book, “The Health Professional’s Guide to Food Allergies and Intolerances” published by the Academy of Nutrition and Dietetics in 2013 for comprehensive lists of the level of salicylates in numerous commonly-eaten foods, and the accompanying consumer handout: “Salicylate Intolerance” for details of the salicylate-restricted diet.

In further answers to the two queries above:

Enquirer A:

I would definitely recommend the histamine-restricted diet for your 7-year old.  Be very careful in replacing all the foods restricted with those of equal nutritional value, especially while you are also restricting his intake of gluten, soy, and dairy products.  I strongly urge you to consult a registered dietitian to assist you in this as it is very difficult to ensure a completely adequate diet on your own. At 7 years of age your son must be provided with all the macro- and micronutrients that are so essential for his growth and development.

Enquirer B:

You have clearly questioned the impact of inflammation on your symptoms.  This would further support the value of a histamine-restricted diet.  I would strongly recommend the latter rather than avoiding the extensive list of salicylate-containing foods, unless you have definite indications of a salicylate sensitivity, following the information I have provided above. 

The question regarding fish oils and inflammation requires a much longer and separate discussion, but I will try to be brief here.  Inflammation involves the release of fatty acids (FA) from cell membranes.  Two are of particular importance; omega-3 and omega-6 fatty acids. They form the basis of inflammatory mediators (chemicals that contribute to, or “mediate” inflammation) called eicosanoids. 

Of the two, the most highly inflammatory are the omega-6 FAs.  Research seems to indicate that if we substitute omega-3 FAs for omega-6 FAs, inflammation will be reduced in severity, but not eliminated altogether. The most important word here is substitute.  In other words, we need to reduce the omega-6 and increase the omega-3 types of FAs.  A ratio of 10:1 omega-6 to omega-3 would be desirable.  The normal diet contains a ratio of about 25:1 or more.  Taking fish oils, flax seed oil and other foods and oils high in omega-3 FAs will increase the omega-3 in your body, but at the same time you will need to reduce the omega-6 in foods such as meats, poultry, milk and others.  You can see that in this case merely taking omega-3 supplements might help, but the effect on your inflammatory condition will be negligible if the FA ratio is not adjusted by a very carefully formulated diet. I doubt very much that you will see any benefit in taking daily flax seed oil and vitamin E, but they are harmless, so not contra-indicated.

You can buy all of Dr Joneja's books here.

First published November 2013

For an in depth investigation into salicylate intolerance see Dr Joneja's article here and for a wide selection of other articles on salicylate intolerance, including some personal experiences see here. For articles on other uncommon allergies and intolerances see here.

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