Allergies are increasing worldwide. And while we know much more about allergies and the immune system today than we knew a few decades ago, there are still many unanswered questions. What elements in allergies are hereditary? Can a mother’s immune system lower cases of food allergies in breastfed babies? Can we take steps to minimize allergies and other immune disorders early in life? Preventing allergies is the focus of many scientists and allergists, and if you ask any of them to suggest a practice that has maximum potential to prevent allergy in children—one that is safe, is acceptable for most families, and has an insignificant cost factor—the most likely suggestion would be breastfeeding!
This might be a slight exaggeration, but it is not without scientific merit. It has been observed that infants who received exclusive breastfeeding up to at least the four initial months of life had less risk of developing atopic dermatitis and asthma later.
Food allergies in breastfed babies: Exclusive Breastfeeding
The term “exclusive breastfeeding” is important here—it means that an infant receives nothing other than breast milk, not even water. The newborn can take medically prescribed drugs and vitamins, however. Importantly, only infants who are exclusively breastfed for at least the first four months are life enjoy the allergy prevention benefits. Infants who receive mixed feeding or partial breastfeeding do not see these immune system benefits.
How Breastfeeding Boost the Immune System in Babies
How does breast milk protect an infant against allergy? Well, Mother Nature has specifically designed the composition of human breast milk for human babies. Not only it is nutritious; it is also protective and aids development of a better immune system. Breast milk is rich in secretory immunoglobulins (S-IgAs), which provide a kind of “local immunity” in infants’ gastrointestinal and respiratory tracts.
Breast milk is also rich in other helpful compounds such as transforming growth factor beta. This compound and similar one stimulate and help infants’ immune systems to mount desirable responses when the encounter new substances. (We know that an allergy is an undesirable immune response to harmless substances). Also, human breast milk is rich in certain organic compounds (like spermine and spermidine) that decrease intestinal permeability in the developing gut of the infant; intestinal permeability plays an important part in developing food allergies. Simply put, food allergies in breastfed babies would potentially be lower than in babies who are not breastfed.
The Other Side of the Coin
However, the picture is not completely rosy. A fetus starts producing IgE antibodies (which cause most allergic disorders) from as early as the first trimester of pregnancy. A developing fetus is exposed to many allergenic substances—both airborne and food allergens—during pregnancy itself, through the mother’s blood. Hence, some allergies can begin even before birth!
Recently, researchers have also found some substances in human breast milk that could induce an allergic response. Such substances are especially present in greater quantities in breast milk of atopic mothers, possibly making their infants more prone to allergies.
In nutshell, human breast milk contains both types of factors—allergy-protecting as well as allergy-inducing ones. Most often, protective factors have the upper hand. Looking at the other benefits of breastfeeding, most scientists, organizations, and governments emphasize the importance of breastfeeding for allergy prevention, protection against infections, better growth and development, and better nutrition. In a few cases, however, scientific opinion may differ.