A soy allergy is an immune reaction to soybean proteins. Many babies who are allergic to cow’s milk will also react to soy-based formulas.
Symptoms of soy allergy:
The symptoms of soy allergy can be divided into 3 categories:
- Gastrointestinal – loose stools or diarrhea, vomiting, stomach pain
- Respiratory – cough, wheeze, asthma, rhinitis (stuffy or runny nose)
- Skin – hives, swelling, eczema
Anaphylaxis is the most severe allergic reaction, involving every above organ system. It can lead to anaphylactic shock and death. Anaphylaxis due to soy allergy is rare.
The soy-free diet:
Following a soy-free diet requires the elimination of the following types of foods:
- Soy sauce
- Soy flour
- Many milk substitutes
- For a more detailed list, read the Soy-Free Guide
Soy oil and soy lecithin may not contain any or enough soy protein to cause a reaction, and therefore may be tolerated by soy-allergic individuals. However, products can also be contaminated with soy protein during processing, so a highly sensitive person may still react to products containing these forms of soy.
Soybeans provide calcium, folate and iron, but these nutrients can easily be found in other foods. Therefore, nutrient deficiency is not a concern when eliminating soy from the diet.