What Is Salicylate Sensitivity?

by | Aug 31, 2022

Ever experienced migraine, mood swings, gastrointestinal, respiratory, and/or skin problems? While there is a multitude of valid medical explanations as to why these unpleasant symptoms occur, one factor that may have been overlooked, especially if symptoms persist after everything else has been explored, is salicylate sensitivity.

Reported as the most widely distributed of the natural chemicals capable of providing symptoms, salicylates can wreak havoc on susceptible individuals. Fortunately, adverse reactions can be kept at bay through dietary interventions and limiting salicylate-laden household products.

The following blog post will discuss salicylate sensitivity: what the chemical is, how it negatively affects certain people, how to diagnose it and what you can do to limit your intake if you find out you don’t tolerate this chemical so well.

What are salicylates?

Salicylates (suh-lih-suh-lates) are a group of chemicals derived from salicylic acid. They are a naturally occurring chemical produced by plants, acting as the plant’s immune system, reducing the risk of pathogens invading and defending against environmental stress.

Known for its anti-inflammatory and fever-quelling properties, salicylic acid as a pain remedy dates back about 4000 years to the Sumerians who utilised willow-tree (the leaves and bark of which contain salicylic acid) as a treatment for pain, fever and inflammation (2). Exploited throughout history, it was discovered that while indeed medicinally useful, prolonged oral use of large doses of salicylic acid caused undesirable side-effects including nausea, vomiting and ulcers. Fast forward to the 1800s, savvy scientists figured out how to enable absorption of the drug without distress whilst still providing therapeutic benefits. Thus Aspirin, a derivative of salicylic acid, was born. It has been called a “drug-delivery system for a natural product that has been in medical use for literally thousands of years” (3). 

Salicylic acid and Aspirin are also known for their disease-preventative use, particularly where chronic inflammation and oxidative stress are main components (4). The effects of consuming fruit and vegetables on lowering disease risk is well documented, and it’s thought salicylates found in plant-based foods could play a role (4).

Due to its antifungal and antibacterial properties, salicylic acid and its derivatives are often used as preservatives in processed foods, condiments, cosmetics, and toiletries. Those without salicylate sensitivity can consume salicylates without harm, it’s only when consumed in very high quantities that they can be dangerous. Unfortunately for a select few, even a small amount of salicylate-exposure can be detrimental, leading to undesirable symptoms and a diminished quality of life.

What is salicylate sensitivity?

While most people don’t have a problem with salicylate-containing foods or medicines, research shows that about 20% of adults with asthma (5), 60% with of people with food-induced itchy rashes, headaches or migraines, 70% of people with irritable bowel symptoms (6) and 75% of children with behaviour problems (7) may be sensitive to salicylates.

Not to be confused with a salicylate allergy, a salicylate sensitivity does not involve the immune system. Instead, it causes reactions by irritating nerve endings in different parts of the body (9). Salicylates can affect one or more systems (e.g. skin, airways, gastro intestinal, nervous system) and chemical intolerance appears to have a genetic component, usually affecting the same system across generations (9).

The degree to which an individual reacts to salicylates depends largely on their threshold for reacting, therefore, it’s helpful to think of symptoms and their relation to salicylates in terms of the “bucket theory”. Eating a lot of food high in salicylates might fill up your bucket straight away, whereas eating smaller amounts of triggering foods over many days may not be enough to produce any symptoms, but instead accumulate in your body until your dose threshold is finally exceeded and a symptoms ensue.

Thanks to increasing interest in food intolerances and food sensitivities and their link to certain health conditions, research has been conducted into the salicylate content of a wide range of commonly eaten foods and drinks. It’s been estimated that the average Australian diet may contain up to 100mg of natural salicylate per day (6), amounts which may have consequences for individuals particularly sensitive to the chemical.

What causes salicylate sensitivity?

Unfortunately, it’s still unknown what exactly causes salicylate sensitivity. In regard to symptoms, it’s thought that they may result from the chemical’s ability to irritate nerve endings in different parts of the body (9). Another theory is to do with the body’s ability to process phenols, but more research is needed to confirm this.

While there is a large body of anecdotal evidence highlighting the link between food sensitivities and health conditions, science has a way to go in proving not only that salicylates indeed cause the adverse reactions experienced by sensitive individuals, but also why these people have a decreased ability to properly metabolize and excrete them from their bodies in the first place.

What are the symptoms of salicylate sensitivity?

The symptoms of salicylate sensitivity vary between individuals, but the most commonly reported ones include:

  • Migraine
  • Asthma-like symptoms (wheezing, trouble breathing)
  • Chronic cough
  • Nasal congestion, runny nose, nasal polyps
  • Itching, skin rash or hives
  • Stomach pain or upset
  • Eczema
  • Tinnitus (ringing of the ears)
  • Urinary incontinence
  • Agitation, aggression, irritability
  • Depression

How do you diagnose a salicylate sensitivity?

The elimination diet is currently the only useful diagnostic tool health care professionals have in investigating salicylate sensitivity. The diet, developed by the Royal Prince Alfred Hospital (RPAH) involves cutting down on a range of food chemicals that are known to cause symptoms in some people. Due to its restrictive nature, the elimination diet should only be applied short-term so as not to starve the body of essential nutrients.

After being on the elimination diet for at least 3-6 weeks and once symptoms have settled for at least 5 days in a row, the next step is introduced, which involves identifying which particular food chemicals are tolerated by the individual, and which ones are not. This food challenge process involves testing each food chemical one by one, usually done by eating foods that provide a high dose of each particular chemical. If no symptoms are experienced during the period where the food chemical is introduced, it’s assumed that foods containing that chemical are safe to eat. However, if symptoms are experienced, then a food trigger is considered to have been successfully identified and it’s now a matter of discovering what an individual’s threshold is for that chemical.

For me, I reacted quite strongly to salicylates after doing the elimination diet. It turns out my threshold for this chemical is quite low, which means I’ve had to limit the amount of salicylates I consume on a daily basis whilst still ensuring I derive sufficient nutrients from alternate food sources.

Elimination diet resource

The RPAH Elimination Diet Handbook is an excellent resource for conducting the elimination diet which outlines which foods you can and can’t eat during the elimination phase as well as which foods are low, medium and high in particular chemicals for the reintroduction phase. The resource also includes a handy elimination diet shopping list and recipe guide.

Please note

It’s very important to consult a dietitian or doctor before conducting an elimination diet as cutting out too many food groups may cause not only a nutritional deficiency, but stress and poor quality of life which can lead to negative health outcomes.

What can I eat if I have a salicylate sensitivity?

Abundant in the diet, salicylates are found in most fruits and vegetables, as well as herbs, spices, most nuts and seeds, honey, tea and coffee. The amount of salicylate varies according to the type of food and can also be found in non-food items such as mint toothpaste, cosmetics, cleaning products and fragrances (a possible reason why lots of migraneurs are triggered by strong perfumes).

The good news is you can still eat very well with a salicylate sensitivity, you just have to be discerning about the types of food you consume throughout the day.

Once you’ve worked out which foods are most likely to fill your “bucket” and trigger symptoms, you can either avoid them completely or distribute them throughout the week so you aren’t consuming ‘high’ salicylate-containing foods all in one sitting. For example, I still eat zucchini, however on days I know I’m going to eat it, I make sure to consume other foods known to have low salicylate content, thus never exceeding my threshold.

I highly recommend purchasing the RPAH elimination diet handbook for a comprehensive overview of the salicylate content of an extensive range of food items. However, while you await your purchase, here is a brief outline of some common food items and products listed as being high in salicylates.

I’ve also written a post on low-salicylate meal ideas if you’re unsure of where to start on your low-salicylate journey.

Foods High In Salicylates Products That May Contain Salicylates Ingredients You May Want To Avoid
Fruits such as apple (granny smith and pink lady) avocado, banana, blueberry, cherry, fig, grape, lemon, orange, dates, dried fruits, mango, pineapple, plums, rhubarb, strawberries, tomatoes Fragrances and perfumes Acetylsalicylic acid
Vegetables such as capsicum, eggplant, olives, onion, mushroom, spinach, radish, broccoli, corn Shampoos and conditioners Artificial food colouring and flavouring
Dried spices and herbs, chili, tomato pastes and sauces, white vinegar, jams, gravy, stock and fermented products Makeup such as lipsticks, lotions and cleansers Mint and spearmint
Luncheon meats, seasoned meats, fish canned in oil and with seasoning Mouthwash and toothpaste Menthol
Nuts such as almonds, macadamia, peanut, pine nut, walnut, pistachio and peanut butter. Muscle pain creams Salicylic acid
Coconut flakes, sesame, honey, corn syrup, vanilla essence Teething gel and oral gels Benzoates
Drinks such as fruit juices, cordials, ginger beer, tomato juice, chai, herbal and black teas, coffee, beer, wine, and rum Acne cleansers and wipes Magnesium salicylate
Peppermints, licorice, chewing gum, mint-flavoured sweets Some insect repellents Sodium Salicylate

Note: I used studies by Malakar et al. 2017Swain et al. 1985 and St. Joseph’s Health Care to verify “high” salicylate foods. The foods I mention are just some examples. Please do your research when looking to identify which foods are low, medium or high saliciylate.

Brigid xx

 

References

(1) Duthie GG, Wood AD. Natural salicylates: foods, functions and disease prevention. Food Funct. 2011 Sep;2(9):515-20. doi: 10.1039/c1fo10128e. Epub 2011 Aug 30. PMID: 21879102.

(2) Norn S, Permin H, Kruse PR, Kruse E. Fra pilebark til acetylsalicylsyre [From willow bark to acetylsalicylic acid]. Dan Medicinhist Arbog. 2009;37:79-98. Danish. PMID: 20509453.

(3) Goldberg, Daniel R. “Aspirin: Turn-of-the-Century Miracle Drug.” Science History Institute, 2009, https://www.sciencehistory.org/distillations/aspirin-turn-of-the-century-miracle-drug. Accessed 23 January 2022.

(4) Duthie GG, Wood AD. Natural salicylates: foods, functions and disease prevention. Food Funct. 2011 Sep;2(9):515-20. doi: 10.1039/c1fo10128e. Epub 2011 Aug 30. PMID: 21879102.

(5) Jenkins C, Costello J, Hodge L. Systematic review of prevalence of aspirin induced asthma and its implications for clinical practice. BMJ. 2004 Feb 21;328(7437):434. doi: 10.1136/bmj.328.7437.434. PMID: 14976098; PMCID: PMC344260.

(6) Loblay RH, Swain AR. ‘Food intolerance’. In Wahlqvist ML, Truswell AS, Recent Advances in Clinical Nutrition. London: John Libbey, 1986, pages 169-177.

(7) Swain A, Soutter V, Loblay R, Truswell AS. Salicylates, oligoantigenic diets, and behaviour. Lancet 1985;2(8445):41-2.

(8) National Center for Biotechnology Information. “PubChem Compound Summary for CID 338, Salicylic acid” PubChem, https://pubchem.ncbi.nlm.nih.gov/compound/Salicylic-acid. Accessed 23 January, 2022.

(9) Swain, A., Soutter, V, & Loblay, R. (2011). RPAH Elimination Diet Handbook with food and shopping guide. Australia: Allergy Unit, Royal Prince Alfred Hospital.

(10) Gray, D. “Food and Drug Administration Memorandum, glutamate in food.” Fed Regist 61.178 (1996): 48102-48110.

(11) Wantke F, Götz M, Jarisch R. Histamine-free diet: treatment of choice for histamine-induced food intolerance and supporting treatment for chronic headaches. Clin Exp Allergy. 1993 Dec;23(12):982-5. doi: 10.1111/j.1365-2222.1993.tb00287.x. PMID: 10779289.

(12) Szczeklik A, Sanak M, Nizankowska-Mogilnicka E, Kiełbasa B. Aspirin intolerance and the cyclooxygenase-leukotriene pathways. Curr Opin Pulm Med. 2004 Jan;10(1):51-6. doi: 10.1097/00063198-200401000-00009. PMID: 14749606.

 

DISCLAIMER: This article is for informational purposes only. It is not intended to constitute or be a substitute for professional medical advice, diagnosis, or treatment. 

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