More and more patients are presenting with the label of salicylate intolerance, and this is super concerning for a number of reasons.
Salicylates are found in all sorts of foods, beauty products, perfumes, preservatives and medications. It’s nearly impossible (well, some would argue impossible) to avoid them completely in daily life in the U.S. Naturally-occurring in plants, salicylates are derivative of salicylic acid. Their role is to protect plants against diseases, bacteria, fungus, and insects.
The beneficial effects of salicylate-containing fruits, vegetables and herbs are well established and documented in the literature. Some studies even suggest that the reason fruit- and vegetable-focused diets reduce cancer risk is because they contain naturally occurring salicylates.1
It’s important to point out that most experts maintain that salicylate sensitivity is not technically an allergy. It’s not mediated by IgE-type allergic reaction pathways. An intolerance or sensitivity is believed to be caused by lack of enzymes and/or abnormalities in other biochemical processes. Dr. Janice Joneja explains this concept well on the following forum:
https://www.foodsmatter.com/allergy_intolerance/salicylate/articles/joneja-11-15.html
In the forum, Dr. Joneja concluded, “It has been my experience that many people are being placed at nutritional risk because of an unconfirmed idea that salicylate sensitivity is at the root of their problems.” I honestly am worried about this as well.
Some experts suspect that factors such as hormonal changes, stress or an infection can be triggers for patients developing food intolerances. I also theorize that leaky gut plays a role in the development of salicylate sensitivity. In a nutshell, changes in our microbiota in the intestines (due to stress, sugar, the Western diet, medications, toxins, etc.) leads to a breakdown in the endothelial lining of the gastrointestinal tract. Specifically, the porous layers of the GI tract remain open for too long due to tight junction/barrier dysfunction. This triggers immune activation of cytokines/other inflammatory mediators, and patients find themselves in a vicious cycle. Food and toxin molecules are then able to be absorbed into the bloodstream, and this can trigger reactions and inflammatory responses.
The concept of salicylate intolerance is not new; researchers and clinicians have looked at this concept since the 1970’s. Anne Swain popularized the discussion about salicylate intolerance in Australia back in the 1980’s. The Feingold and Failsafe Diets are the eating plans most traditionally prescribed for patients who are suspected to exhibit salicylate sensitivity.
The Feingold diet has been studied fairy extensively for treatment of ADHD and autism, but not in patients with MCAS and not specifically in patients demonstrating salicylate intolerance. (Part of the research difficulty lies in the fact that there’s no clinical test to “diagnose” someone with salicylate intolerance, though some clinicians will do an oral provocation test using aspirin.)
Feingold’s development of the diet stemmed from noting behavioral problems in patients who were aspirin-sensitive. The few studies evaluating variations of this diet have not focused on natural salicylates in food, and instead have generally included a focus on eliminating preservatives and artificial food additives, so our ability to extract insight is somewhat limited. The research about whether the Feingold diet is effective with conditions such as ADHD and autism appears to be muddy and inconclusive. Likewise, no compelling evidence exists yet to support or refute the theorized link between salicylates and depression or schizophrenia. Similar to histamine, there also appears to be a lot of discrepancy in terms of scientific data reporting salicylate values in different foods.2
A 2014 review2 concluded that:
- Studies that have specifically tried to isolate the effect of salicylates (which is only one of the several elimination items in a typical Feingold diet) are few, and in those the effect of naturally occurring salicylates in common food items has not been studied.
- Pharmacological doses would seem unlikely to be achieved by dietary salicylates.
- A diet low in natural salicylates is likely to be deficient in some of the essential ingredients of an otherwise healthy diet.
- There is a present and urgent need for both broader as well as deeper investigations that would academically inform the pertinent disciplines and improve the current state of clinical practice, especially when advocating typical ‘healthy’ eating plans.
- It is only after a causal link has been empirically established between dietary intake levels of salicylates and the risk of exacerbated symptom severity for behavioural disorders, that one can then look at the other related problem areas, e.g. formulation of alternative diets and ensuring better compliance to dietary regimen.
Similar to the concept of avoiding histamine in foods, for some patients, the logic in avoiding salicylates (dietarily) seems flawed. Obviously, it’s not black and white, and there’s a big difference between a patient who has severe anaphylaxis to ALL salicylates, vs. the one who just reacts to higher content sources like aspirin, vs. the patient who has mild to no symptoms but tends to react spontaneously to random foods.
Some patients react only to synthetic salicylates and have no discernible issues with natural salicylates, but decide to eliminate all sources from their diet, which can lead to problems. There are many low- to no-salicylate fruits and veggies and they pale in comparison to the content of things like medications and beauty products. Experts maintain that a typical diet is not expected to exceed the salicylate levels of 325-650mg of aspirin.
Just like histamine, the growing conditions, food preparation techniques and level of ripeness can influence the salicylate levels on food sources. Just like histamine, salicylates are found on many healing/antioxidant food sources (like fruits and vegetables) which are (in my mind) essential to restore homeostasis and reverse disease inflammation. Salicylates themselves are anti-inflammatory, and cutting them out “blindly” can be extra restrictive/detrimental to healing in most scenarios. And just like histamine, patients with MCAS often confide that trying a “low salicylate” diet on top of an already restrictive list of options makes them more and more sensitive/reactive over time, and more and more sick, until they are down to very few “safe” foods.
The lists of salicylate-containing foods on the internet make me cringe. One website advocated that patients focus on breads, cereals, and noodles/pasta while having to completely avoid sweet potato. I believe that we have way too much tunnel vision here, and we need to look at nutrient factors and healing potential as a whole, instead of having patients memorize ridiculous lists of yes and no foods. (Again, I realize that some patients are severely ill/sensitive and must remove certain foods on the basis of anaphylaxis and what they personally react to. But I want to discourage patients from blindly following internet food lists regardless of what their body is telling them.)
This brings me back to my age-old question of, why do we keep putting a Band-Aid on symptoms instead of getting at the root issues for why the immune system is struggling? Forgive me for the soap box, but I’m so tired of witnessing patients go down this rabbit hole of investigating every single type of label regarding food intolerances to explain their symptoms, instead of figuring out why their system is so inflamed and reactive in the first place.
References:
- Paterson, J.R. & Lawrence, J.R. (2001): Salicylic acid: a link between aspirin, diet and the prevention of colorectal cancer. Q. J. Med., 94, 445–448.
- Malakar, S., & Bhattacharya, S. (2014). MINDING THE GREENS: ROLE OF DIETARY SALICYLATES IN COMMON BEHAVIOURAL HEALTH CONDITIONS. Budapest Acta Alimentaria, 43(2), 344–359. https://doi.org/10.1556/AAlim.2014.0017
