Salicylate intolerance is not fully understood by scientists.
The condition is often misdiagnosed, and there is a variety of possible treatments.
Some salicylates are relatively easy to stay away from, but others are nearly impossible to avoid.
This article looks at the evidence-based ways to treat salicylate intolerance.
- What Are Salicylates?
- What Is Salicylate Intolerance?
- Signs and Symptoms of Salicylate Intolerance
- Food Sources of Salicylates
- Does Salicylate Intolerance Cause Other Digestive Diseases?
- Treatments For Salicylate Intolerance
- Is a Low-Salicylate Diet Necessary?
- A Low-Salicylate Diet Plan
- Fish Oil For Salicylate Intolerance
- We Have Much More To Learn
What Are Salicylates?
Salicylates is the general term for chemicals that have salicylic acid as their base.
Salicylic acid is a naturally-occurring organic acid found in a variety of plants. These plants produce it as part of their defense system against diseases, insects, bacteria and environmental stress.
Salicylic acid is used as an ingredient in synthetic salicylates and a variety of other products. Aspirin, for example, is made by combining salicylic acid with a chemical called acetic anhydride.
Summary: Salicylates are a group of chemicals that form part of a plant’s natural defense system. They are also used as ingredients in a variety of products.
What Is Salicylate Intolerance?
Most tolerate regular amounts of salicylates without any issues.
However, in some people even a small dose can cause problems. This is called salicylate intolerance or salicylate sensitivity.
The percentage of people suffering from salicylate intolerance is unknown but it appears to occur more often in adults than children (1).
The only type of salicylate that has clearly been shown to cause negative reactions in those with salicylate intolerance is acetyl salicylate (in aspirin) (2).
The amount of salicylates in regular aspirin is typically 325 mg. Extra-strength aspirin or arthritis pain relievers can contain 600–650 mg.
In comparison, daily intake of salicylates from food is estimated to be 10–200 mg on average (3).
While foods containing salicylates may be able to cause similar reactions to aspirin, there is no current research to confirm this. And since pain relievers are often taken multiple times a day, the potential amount of salicylates from medication can vastly outweigh those from from foods.
As with other intolerances, such as histamine intolerance, the amount of salicylates consumed probably determines whether symptoms occur. Most people with sensitivities can tolerate at least a small amount.
Summary: Salicylates do not cause problems for most people, however those who are sensitive will react to small amounts. Aspirin is by far the largest source for humans.
Signs and Symptoms of Salicylate Intolerance
Typical signs and symptoms of salicylate intolerance include (1):
- Sinus inflammation and infection
- Polyps (small, non-cancerous growths) in the nasal and sinus passages
- Tissue swelling
- Inflammation of large intestine, which can cause abdominal pain and discomfort
As symptoms of salicylate intolerance can appear very similar to an allergy (hives and sinus problems, for example), it is often misdiagnosed. In fact, for some people salicylates only cause symptoms when they are experiencing allergies, making it even harder to separate the two (5).
However, unlike an allergy, salicylate intolerance doesn’t involve the immune system.
Salicylate intolerance is also more common among adults with asthma. It’s been estimated that 2–23% of asthmatics are sensitive to aspirin (4).
The mechanism by which aspirin and other pain relievers containing salicylates affect asthma is not clear but it can have devastating consequences. In severe cases, a single dose of aspirin can cause a person to lose consciousness and stop breathing (4).
Summary: Symptoms of salicylate intolerance often include asthma, hives, sinus problems and nasal polyps. These symptoms are sometimes mistaken for allergies.
Food Sources of Salicylates
Many foods naturally contain salicylic acid.
Reported levels of salicylates in foods differ somewhat, likely due to differing methods of analysis and the growing conditions and varieties of plants tested.
In general, the highest amounts of salicylates are found in fruits, vegetables and spices. Cereals, meat, fish and dairy products contain very little or none (3).
Based on weight, herbs and spices have the highest concentrations of salicylic acid. Curry powder, for example, has been reported to have 218 mg per 100 grams of powder (3).
For comparison, raspberries are reported to have 4.4 mg per 100 grams and they are considered a high salicylate food.
Click to enlarge.
Other Sources of Salicylates
Many health and beauty products and household cleaners also contain salicylates.
They serve a variety of functions in these products including as fragrances, preservatives, exfoliants, conditioners, and anti-dandruff and anti-acne agents.
Click to enlarge. Source.
Summary: Salicylates are found in many foods, medicines, cosmetics and household cleaners. Foods with the highest amounts include spices, fruits and vegetables.
Does Salicylate Intolerance Cause Other Digestive Diseases?
Some data suggests that salicylate intolerance may cause other diseases of the digestive tract, including inflammatory bowel disease and food allergies.
One group of researchers suggested that 2–7% of patients with these conditions may also have salicylate intolerance (1).
The authors suggested that the possibility of salicylate intolerance should be considered among all patients with ulcerative colitis or food allergies.
Summary: Salicylate intolerance may be more common in those with food allergies or Ulcerative Colitis. However, scientists are unsure exactly how the conditions are related.
Treatments For Salicylate Intolerance
Avoiding aspirin and other salicylate-containing medications is the first line of defense for those with salicylate intolerance.
Switching to cosmetics and cleaners without salicylates may also be helpful.
In some cases, treatment with steroids, other medications or even surgery to remove respiratory growths may be necessary (5).
Desensitization is another treatment sometimes used. The patient is given daily doses of acetyl salicylate, and the dose is slowly increased over time. In about 80% of cases, improvements in ease of breathing, sense of smell and freedom from recurring polyps are observed (6).
Desensitization should only be undertaken with a physician’s care. The first phase is often done in a hospital, since adverse reactions, including asthma, can occur (5).
Summary: Avoidance of aspirin and other salicylate-containing products may be necessary for those with a salicylate intolerance. In some cases, medications, surgery or desensitization treatment may be suggested by a physician.
Is a Low-Salicylate Diet Necessary?
For adults who have found no other treatments helpful, a low-salicylate diet is worth consideration (9).
However, there is currently no scientific proof this form of elimination diet is of any benefit (10, 11). In fact, anecdotal reports indicate a low-FODMAP diet may be the better alternative, which is scientifically shown to help treat food intolerance.
Unfortunately, elimination diets are not really appropriate for children.
One study of 74 children put on an elimination diet for salicylates found that almost half experienced harmful side effects. This included nutrient deficiencies, food aversions and eating disorders (7).
Nutrient deficiencies during childhood can have long-lasting impacts on health and development (8). For these reasons a low-salicylate diet (or other elimination diet) should be the last line of treatment for children.
Summary: In severe cases, adults may trial a salicylate-restricted diet (followed by reintroduction) or a low-FODMAP diet. Elimination diets are not usually recommended for children.
A Low-Salicylate Diet Plan
Adults with a high sensitivity to aspirin who have found no relief from other treatments may wish to try a low-salicylate diet.
Important tips to keep in mind:
- Only foods with the highest levels of salicylates should be avoided (see list above).
- Restrict high-salicylate foods for a maximum of 4 weeks.
- Slowly reintroduce high-salicylate foods, noting any symptoms that occurs in a food and symptom diary.
- Be sure to include plenty of fruits and vegetables that are not on the high-salicylate list.
Here is an example of a realistic 3-day low-salicylate diet plan:
Breakfast: Cereal with milk; banana.
Lunch: Salad with mixed lettuce, chicken breast, shredded carrots, shredded cheese and dressing; apple.
Dinner: Baked fish with brown rice and roasted cauliflower.
Snacks: Yogurt; pear.
Drinks: Water; milk.
Breakfast: Yogurt with granola and sliced pears.
Lunch: Sandwich with wholegrain bread, sliced turkey breast, lettuce, tomato and cheese.
Dinner: Burritos with wholegrain tortillas, black beans, cheese, lettuce and avocado.
Snacks: Carrot sticks with hummus; string cheese; apple.
Drinks: Water; milk.
Breakfast: Oatmeal with walnuts and chopped apples.
Lunch: Tuna sandwich on wholegrain bread with lettuce and tomato; carrot sticks; pear.
Dinner: Baked chicken with mashed potatoes and green beans.
Snacks: Pecans; banana; wholegrain crackers with sliced cheese.
Drinks: Water; milk.
If you feel a low-salicylate diet plan may help you, see a registered dietitian to help you plan an appropriate balanced diet.
Fish Oil For Salicylate Intolerance
Looking at supplements, only fish oil may has been examined for salicylate intolerance.
One small study reported on three patients with extreme intolerance to salicylates, including severe hives and asthma.
After taking fish oil for 6–8 weeks, all three experienced complete or nearly complete improvement of their symptoms. The authors suggested that daily supplementation with 10 grams of fish oil rich in omega-3 fatty acids appears to be a safe and effective treatment for salicylate intolerance (12).
Unfortunately, due to the study size and quality we can’t make any recommendations until more research is complete. Additionally, 10 grams of fish oil per day is incredibly high and should be done under medical supervision.
Summary: Very early evidence suggests 10 grams per day fish oil supplementation may help treat salicylate intolerance. However, this is based on a weak study.
We Have Much More To Learn
Salicylate intolerance is a poorly understood condition.
Treatment can be difficult as it shares symptoms with many allergies and other food intolerances.
Salicylates are also present in a wide variety of foods, medicines, cosmetics and other products, making them difficult to minimize.
The most important step is to eliminate exposure to aspirin and non-food sources of salicylates. If there is no improvement, consider reducing food sources too with either a low salicylate diet or a low FODMAP diet.
Always talk with your doctor before making any changes.