What is Soy Intolerance?

Soy intolerance is a non-allergic, hypersensitive reaction to soy. By definition, an intolerance of soy is not the same as a soy allergy. A food allergy is an immune system response that specifically requires the presence of the Immunoglobulin E (IgE) antibody, whereas food intolerance is caused by an inability to properly digest certain foods and/or absorb nutrients sufficiently.

Quite a bit of controversy surrounds soy products. Some people believe that soy is a heart-healthy, protein-heavy miracle plant. Along with its popularity, criticisms about the dietary benefits of soy have grown louder. Some skeptics have gone so far as to say that the human digestive system itself is intolerant of soy.

Soy protein is used as an alternative to cow's milk protein in baby formula for infants with dairy intolerance. Unfortunately, many of the babies who are given soy protein because of their dairy intolerance also develop a soy protein intolerance. For this reason, it is no longer recommended that soy protein be used as a milk alternative for babies.

Soy intolerance can cause digestive problems, such as cramps, diarrhea, nausea or vomiting. It can cause breathing problems, heart palpitations or a drop in blood pressure. Intolerance of soy can induce hives, rash and swelling of the neck or face. The swelling can affect the eyes, lips or tongue. Severe reactions to soy intolerance, such as anaphylaxis, are very rare.

Identification of soy intolerance is often difficult. Physiological reactions to soy intolerance might take anywhere from 20 minutes to 48 hours to appear. It is difficult to figure out which food is responsible for the symptoms, because a person typically will have eaten as many as six different meals during that time period.

After it has been identified, soy intolerance is fairly simple to treat. As with all other food allergies and intolerances, soy must be eliminated from the person's diet. Soy is one of the most common ingredients used in foods processed in the United States and many other countries. An individual who soy intolerance should be very careful when checking food labels.

An individual might be able to diagnose himself or herself with soy intolerance. If the manifestations are mild, the individual can remove soy from his or her diet and see if that relieves the symptoms. Usually, it's a good idea to talk to a professional nutritionist or doctor about the symptoms that are present in order to receive a proper diagnosis.