Which Foods Contain Salicylic Acid?

Finding salicylic acid in food might be easier than you think, as numerous foods contain some level of this naturally occurring substance. If you have a salicylic acid sensitivity, be sure to read all packaged food labels before buying a product that may contain this chemical substance.

The word "salicylates" is technically a scientific term, but it simply refers to a chemical that has a salicylic acid base, explains Sexton's Diet vs Disease article. This organic acid occurs naturally in numerous plants, which formulate it as a defense mechanism. In theory, the salicylic acid protects the plants against insects, bacteria, diseases and environmental stressors.

A surprising number of foods also contain some amount of salicylic acid, says the Diet vs Disease article. Fruits and vegetables contain the highest quantities of salicylic acid. In contrast, herbs' and spices' salicylic acid concentrations are based on the foods' respective weights. Using that metric, these foods have the highest salicylic acid concentrations.

Vegetables that contain very small amounts of salicylic acid include fresh carrots, fresh mushrooms, onions, pumpkin and frozen spinach. Canned corn, non-iceberg lettuces, parsley, red potatoes and snow peas contain moderate amounts of salicylic acid.

You'll find higher amounts of salicylic acid in broccoli, cucumbers, fresh spinach, sweet potatoes and tomatoes. Canned mushrooms, radishes, sweet peppers, tomato sauce and zucchini have extremely high salicylic acid concentrations. Quite interestingly, different forms of the same vegetable variety can contain different salicylic acid concentrations.

​Read more:​ The 18 Most Nutritious Vegetables

Many topical skin care treatments, such as salicylic acid gel, contain some form of salicylic acid, states the Mayo Clinic. Although you can obtain most salicylic acid products for skin without a doctor's prescription, some do require one.

Topical-form salicylic acid treats skin disorders such as acne, psoriasis and seborrheic dermatitis. If you're bothered by calluses or corns or have been affected by common or plantar warts, you might be familiar with a product that contains this well-known substance.

Note that these topical skin treatments differ in their respective preparation strengths and forms of dosage. In fact, your neighborhood pharmacy or big box retailer probably carries salicylic acid for skin products in a huge array of dosage forms.

Depending on the application, you might encounter creams, ointments, lotions, foams or liquids. Soap, moistened pads, salicylic acid gel or jellies and shampoo are also common, as are extended-release patches that keep delivering more medication over a period of time.

Most people won't encounter any negative effects from consuming salicylic acid in food or using salicylic acid gel and can tolerate regular amounts of salicylates without any issues.

However, in some people even a small dose can cause problems and some unlucky diners may find they have a food intolerance to the salicylates in their latest meal, says Montana State University. This is called salicylate intolerance or salicylate sensitivity.

A food intolerance rears its ugly head when a food substance turns your digestive system upside down, explains the Cleveland Clinic. A food intolerance can also occur when your body doesn't have the enzymes to properly digest a specific food you just consumed, such as with a lactose intolerance.

Food intolerances can also result from the addition of special-purpose chemicals that are added to certain foods. These substances are designed to improve the food's taste, add inviting color and ward off bacteria growth.

Food intolerance symptoms can be rather unpleasant, but are generally less serious than an immune system response triggered by a food allergy. After you consume an offending food, you could experience stomach pain, heartburn or bloating. Nausea, gas, diarrhea and vomiting are also common food intolerance symptoms. To make matters even worse, you might become irritable or develop a nasty headache.

Some food intolerance incidents depend on the amount of the food consumed. For example, if you're gluten intolerant, you may be able to crunch a few wheat crackers with no ill effects, but eating a piece of bread may trigger nasty symptoms.

​Read more:​ 9 Foods You Didn't Know Contain Gluten

If you've had an unpleasant reaction after consuming salicylic acid in food, you may have decided (perhaps with your physician's guidance) to drastically limit your salicylates intake. A small study, published in the ​Pomeranian Journal of Life Sciences​ in 2016, tracked the nutritional effects of a low-salicylate diet.

Researchers knew that elimination diets can lead to nutrient shortfalls, and they wanted to determine if a low-salicylate diet would have the same negative effects. They used nutrition software to evaluate 30 diets for their respective nutritional content.

Researchers placed 10 subjects in each of the three 1,500, 2,000 and 2,500 daily calories groups. Each diet's average nutritional content was compared to then-current adult dietary standards.

The study's conclusions weren't exactly encouraging. For both men and women, a 1,500-calorie reduced-salicylate diet provided abysmal nutritional results. Although different genders and age groups varied in their nutrient deficiencies, each group lacked specific nutrients while on this diet. However, the two higher-calorie low-salicylate diets didn't present any special nutritional risks.

Certain people can also experience a salicylate sensitivity after taking a dose of aspirin, says Sexton's Diet vs Disease article. Although this intolerance can cause allergy-type symptoms, a salicylate sensitivity has nothing to do with your immune system.

Adults are more likely to be affected by a salicylate sensitivity than children. Adults who have asthma are more likely to have a salicylate intolerance too.

If you're impacted by a salicylate intolerance, you might notice the appearance of hives, or your tissues could swell. Your sinuses may become inflamed, and you may be affected by a sinus infection. You may even develop small polyps in your sinus and nasal passages and have a fever.

At the other end of the spectrum, a salicylate intolerance can cause unpleasant diarrhea episodes. If you feel abdominal discomfort and even pain, an inflamed large intestine may be the culprit. Consult with your physician, who may be able to provide some relief.