“A” Is for Allergy Prevention and Reduction

Breastfeeding plays a significant role in protecting children from developing or exacerbating food allergies. In the American Scientist article “Why We Develop Food Allergies,” researcher Per Brandtzaeg outlines the factors that contribute to a food allergy incidence of more than one in 20 young children in the industrialized world. 

With respect to food allergies, what are the main protective effects of breastfeeding?

1. Breast milk provides key antibodies that keep harmful substances from penetrating the digestive tract. The risk of food allergy is higher when antibody levels are insufficient.
2. “[H]uman milk also contains immune cells, immune-regulating cytokines and growth factors that exert positive biological effects.”
3. When solid foods are introduced (preferably around six months of age), breastfeeding continues to provide protective effects by helping the digestive system tolerate certain food antigens. For example, breastfeeding is known to provide significant protection against wheat gluten-triggered celiac disease.
4. Of course the general recommendation is for breastfeeding to continue for at least one full year or more. Another reason to continue and to wean slowly when the time comes? The protective effects mentioned above lead researchers to surmise that gradual rather than abrupt weaning helps develop a greater tolerance to food proteins. “Mixed feeding”–continued breastfeeding alongside the consumption of solids–may reduce food allergies.
5. A majority of studies show that breastfeeding also protects against asthma and eczema.

Babies are born with an immature immune system and an immature digestive tract.  The immune system utilizes antibodies to bind harmful foreign substances to the surface of the digestive tract and keep them from permeating the tract wall. The primary antibody at work is secretory immunoglobulin A (SIgA). Because a newborn baby produces little or no SIgA, the baby relies on the mother’s breast milk as the only significant source of SIgA antibodies. It can take up to 10 years for a child’s ability to produce SIgA to mature. The process speeds up in developing countries where children are exposed to more microbes than children in developed countries with higher levels of cleanliness. (I’m not the world’s tidiest homemaker–all in the name of protecting my children from allergies! Yeah, that’s it!)

As an interesting side note, children whose mothers have allergies are at least eight times as likely to develop food allergies if they are born by cesarean section. It’s believed that is because the infants are not exposed to certain microbes in the mother’s birth canal.

What if, in spite of all the protective effects of breastfeeding, the child of a breastfeeding mother does develop allergies? She can eliminate the offending foods from her diet and continue to provide the protective benefits of breastfeeding. But what if a child is allergic to milk? Children who are allergic to dairy are allergic to a cow’s milk protein that passes through the mother’s milk. They are not ”allergic to breast milk” and a mother may eliminate dairy from her diet and continue to breastfeed. It’s important to note that if a mother chooses to switch the child with dairy allergies to artificial baby milk, she cannot of course choose a cow’s milk-based product. Not only is soy-based milk controversial but soy is almost as common an allergen as cow’s milk. If the child also happens to be allergic to soy, it may be necessary to rely on very expensive prescription baby milk.