Soy-Free Chronicles: Navigating the World of Soy Allergies

Where is soy found?

Soybeans are used in many different ways. They are often added to flours for baking and eaten whole as edamame. The seeds are also turned into oil which is then incorporated into salad dressings, margarine and baby food. Soy is also used to manufacture tofu. Fermented soy is used in soy sauce and Worchestire sauce. Soybeans and their derivatives are also found in many processed foods including infant formula, processed meats, baked goods and energy bars. 

Allergic reactions to soy

Soy allergy is common in infants and young children, however most children outgrow their allergy by age 10. 

Allergic reactions to soy are usually mild to moderate but can sometimes be severe, although this is rare. 

Symptoms will start within a few minutes to hours after eating a soy product. These include skin reactions like swelling of lips, a rash, hives, wheezing, difficulty breathing, runny nose, stomach pain, nausea, vomiting or diarrhoea. More severe symptoms can include swelling or tightening of the throat, coughing, turning blue or pale,  weak pulse and confusion. 

Some people with soy allergy may also experience symptoms when eating other seemingly unrelated foods. It is more common in patients with seasonal allergies, up to 25% of patients and is associated with a condition called Oral Allergy Syndrome. Patient’s with this condition experience a phenomenon called cross-reactivity that occurs when your body’s immune system identifies the proteins in these different foods as being structurally similar. Some common cross-reactivities are with fruits like apples and cherries, vegetables like carrots, legumes, and tree nuts. These symptoms are often mild and include an itchy mouth and hives on the mouth, scratchy throat, itchy ears, and mild swelling of the lips and mouth. This condition is not life threatening. 

What foods should I avoid with a soy allergy?

Soybeans alone are not a common food in the western diet, however their derivatives are extremely prevalent in processed foods and often difficult to avoid. 

Avoid any foods that contain soy including soy milk, cold-pressed, expelled, or extruded soy oil, edamame, miso, natto, okara, shoyu, soy protein, soya, tamari, tempeh, and tofu. 

Soy is sometimes found in infant formula, asian cuisine (where there is a high risk of cross contamination), vegetable gum/starch, vegetable broth, canned fish, low-fat peanut butter, cereals, butter substitutes, powdered meal replacers, shortenings, high protein bread, candy, chocolates, meat products and canned soups.

The following ingredients, which can appear on food labels may contain soybean protein - bulking agent, carob, emulsifier, guar gum, gum arabic, monosodium glutamate, protein extender, and textured vegetable protein. 

What about soybean oil?

Highly refined soy oil as well as soy lecithin (a mixture of fatty substances derived from soybean processing) can be safely consumed by those with a soy allergy. Ask your allergist if these are safe for you. 

Cold-pressed, expelled, or extruded soy oils - sometimes called gourmet soy oils should always be avoided. These are not highly refined and may contain small amounts of soy protein. 

Should I be avoiding peanuts?

The answer is “not necessarily.” Soybeans and peanuts are two different foods with different allergens associated with each. A person is no more likely to be allergic to peanuts than they would be to any other food. 

To discover a wide variety of soy free options, visit  www.myWellabee.com

Resources

1. FARE (Food Allergy Research and Education)

2. Australian Society for Clinical Immunology and Allergy 

3. American College of Allergy, Asthma & Immunology. Arlington Heights, IL: American College of Allergy, Asthma & Immunology; 2014 [2019 Apr 9]. Available from: https://acaai.org/allergies/types/food-allergies/types-food-allergy/soy-allergy.

4. Mayo Clinic [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2019 Sep 14. Available from: https://www.mayoclinic.org/diseases-conditions/anaphylaxis/symptoms-causes/syc-20351468.