Allergies Center

Soy formula has not been shown to protect high-risk babies from developing allergies or food intolerance.

Allergy and food intolerance are relatively common in children. They can be caused by various foods, including cow's milk products. Usually, though, the chance of a young child developing a food allergy is fairly small. The risk climbs though, if a close relative has an allergy. For example, 7 out of 10 babies develop allergies if both their parents have them. If just one of their parents or siblings has an allergy, then 3 out of 10 babies are at risk.

Out of the options for feeding babies, breastfeeding has the highest chance of helping a baby avoid developing an allergy. If a baby cannot be breastfed, there are several options. The most usual alternative is a formula based on cow's milk. Other options often used particularly to try to avoid allergies are soy-based formula or so-called hydrolysed formula. A hydrolysed formula is one where a protein in either cow's or soy-based milk has been broken down into parts. Proteins can be the cause of allergies. The hope is that by disrupting this protein, allergies will be avoided. Hydrolysed formulas are usually more expensive than ordinary formulas.

Researchers analysed the results of trials that tried to answer the question, whether soy formula might really be able to protect a baby from developing an allergy. They found three trials, which included more than 700 babies at higher risk of developing an allergy or food intolerance.

The result was that soy formula was not more protective against eczema or asthma than ordinary cow's milk formula. There were even some reports that soy formula led to the baby developing an allergy to soy. The researchers concluded from their analysis that soy formula has not been proven to prevent allergies.

None of the trials could answer the question of whether the choice of formula in the first six months has an impact on the risk of allergies in later years.

Causes, incidence, and risk factors

Allergies are relatively common. Both genetics and environmental factors play a role.

The immune system normally protects the body against harmful substances, such as bacteria and viruses. It also reacts to foreign substances called allergens, which are generally harmless and in most people do not cause a problem.

But in a person with allergies, the immune response is oversensitive. When it recognizes an allergen, it releases chemicals such as histamines. which fight off the allergen. This causes itching, swelling, mucus production, muscle spasms, hives, rashes, and other symptoms, which vary from person to person.

Common allergens include pollen, mold, pet dander, and dust. Food and drug allergies are common. Allergic reactions can also be caused by insect bites, jewelry, cosmetics, spices, and other substances.

Some people have allergy-like reactions to hot or cold temperatures, sunlight, or other environmental triggers. Sometimes, friction (rubbing or roughly stroking the skin) will cause symptoms.

A specific allergy is not usually passed down through families (inherited). However, if both your parents have allergies, you are likely to have allergies. The chance is greater if your mother has allergies.

Allergies may make certain medical conditions such as sinus problems, eczema, and asthma worse