Soy Allergy

Individuals diagnosed with soy allergy must learn how to avoid foods that contain soy and soy products. Avoiding these items is not an easy task as the soybean is a legume and the legume family is extensive. You or your doctor may not know exactly what soy product in the legume family you are allergic to and so you may have to avoid all legumes because they may contain soy.

Soy allergies are common in infants and can usually be outgrown by the time they reach 2 years of age. Adults can also suffer from soy allergy although it is rare.


Those allergic to soy may exhibit the following symptoms: acne, eczema, swelling, congestion of the nasal passages, asthma, canker sores or fever blisters, gastrointestinal problems including diarrhea or colitis, eye infection (conjunctivitis), shortness of breath, fever, fatigue, weakness, nausea, the occurrence of low blood pressure, itching, and also hives.

It is important that parents or adults with soy allergies check product labels before buying to be sure that soy or soy products, or soy-containing foods are not being accidentally purchased.

Soy products include soy flour, soy nuts, soymilk, soy sprouts, soybean granules, soy curds, and also tofu.

Soy-containing ingredients include soy protein, Textured vegetable protein (TPV), hydrolyzed plant protein, hydrolyzed soy protein, hydrolyzed vegetable protein, both natural and artificial flavoring, vegetable gum, and also vegetable starch.

Foods that can contain soy are: soy sauce, Miso, Worchestershire sauce, Tamari, Tempeh, vegetable broth, certain cereals, certain infant formulas, and also some baked goods.

Soy is often used in fast food restaurants and 60% of processed foods have soy listed as an ingredient.

It is common for individuals with soy allergy to also be allergic to legumes including peas, peanuts, lentils and garbanzo beans.

Infants allergic to soymilk can be placed on rice milk.

It is difficult to avoid soy when allergic to it, as it is often an ingredient in many processed foods, infant formulas, cereals and salad dressings.

There is a botanical relationship between soy and peas, green beans, peanuts, and carob. Kids allergic to soy are sometimes also allergic to these legumes.

An allergic reaction to soy can be mild or it can be life-threatening anaphylaxis.

A person allergic to soy (adult, child or baby) should avoid anything that has “soy” on the ingredient list, or that is a soybean, soy protein, soy sauce, or the new product soy nut butter. Some kids that are allergic to soy can tolerate soy oil or soy lecithin so your allergist is your best source for what needs to be avoided and what is ok to consume.

It is a must to read ALL labels when you have someone in your family that is allergic to soy.

The medication Benadryl® Fastmelts contain soy protein, so check with your pharmacist and let them record your soy allergy and run checks against any medication that is prescribed for you.

Your healthcare provider or allergist can provide you with a complete list of all the soy protein products to avoid.

Image: Alex Williamson, Wellcome Images