What Is a Soy Allergy?

A soy allergy is an allergic reaction to the consumption of soybeans or foods that use soy derivatives as an ingredient. It results from your body’s immune system identifying soy as a threat to your health. Soybeans are an edible legume or pod plant, similar to peas, lentils, chickpeas, lima beans, pinto beans, navy beans, and peanuts. Soy allergies are most common in infants and young persons but can persist into adulthood. The majority of symptoms are unpleasant, if relatively mild, but can, in rare instances, be fatal.

Allergies are a common form of illness. It is estimated that as many as 50 million Americans may suffer from some type of allergy. Symptoms range from moderate to severe. In rare cases, allergies can lead to anaphylactic shock and death. If you or a loved one are dealing with soy allergy symptoms, see your Baptist Health physician for consultation and treatment.

Am I Allergic to Soy? What Are the Symptoms?

You might be allergic to soy if, after consuming a food with soy or soy extracts, you experience any or a variety of the following symptoms:

• Runny nose
• Ragged or labored breathing
• Coughing or wheezing
• Tingling sensation in the mouth
• Dermatological reactions, such as itching or hives
• Flushed skin (redness)
• Swelling of the lips, tongue, face, or hands
• Nausea, vomiting, and diarrhea

What Foods Commonly Contain Soy?

Soybeans can be consumed in various forms, including as soy flours, nuts, sprouts, and proteins. Soy is also a popular food additive. You may find it in:

• Many Asian foods
• Meat substitutes and fillers, such as tofu or bean curd
• Broths and soups
• Canned tuna
• High-protein energy bars
• Food flavorings
• Frozen meals (“TV dinners”)
• Some cereals
• Some types of peanut butter
• Condiments, including soy sauce, mayonnaise, and Worcestershire sauce

Soy is also commonly found in infant formula. This is one reason why soy allergies often first appear in young children, typically under the age of three. In many cases, the allergy resolves itself by adolescence.

What Is the Difference Between a Soy Allergy and a Soy Intolerance?

Some persons have a mild variation on a soy allergy called a soy intolerance. Unlike a food allergy, an intolerance does not cause the body’s immune system to produce antibodies to the introduced substance. Persons with intolerances can often eat small amounts of the food in question without much difficulty. In larger quantities, they may experience a gastrointestinal reaction, such as an upset stomach or abdominal cramping.

What Are the Risks of a Soy Allergy?

Besides symptom unpleasantness, the primary risk of a soy allergy is anaphylaxis, which is the sudden and severe onset of multiple allergy symptoms, and may result in difficulty breathing, accelerated pulse, dizziness, drops in blood pressure, a state of shock, and death. Anaphylaxis should be addressed as a medical emergency. It is treated by medical personnel with the administration of intravenous fluids and one or more epinephrine (adrenalin) injections. Allergy sufferers should carry an epinephrine autoinjector with them at all times. In case of a children’s allergy, a responsible adult should maintain and administer the autoinjector.

Fortunately, anaphylaxis is rare in soy-allergy sufferers. If you have questions about your level of risk, or that of a loved one, see your physician.

How Do I Prevent a Soy Allergy?

When it comes to soy allergies, the only treatment is prevention. Individuals with soy allergies need to avoid eating anything that contains soy or soy products. This can be a challenge, because a great number of foods now utilize soy as an ingredient. In the U.S., any food that contains soy must list it on the product label. Persons with soy allergies should read all product labels before consuming their contents.

One possible exception involves highly refined soy oils, which some allergy sufferers can eat without triggering a response. Lecithin, a fatty substance derived from soybeans, is a second possible exception. Ask your physician or allergist for assistance in determining whether these exceptions would work for you.

Learn More About Soy Allergies from Baptist Health

Soy allergies can be surprisingly common, even among adults. For more information about soy allergy diagnosis and prevention, talk to your Baptist Health physician.