Can breastfeeding reduce risk of allergies for your child?

Food allergies are on the rise among the next generation. There are several theories as to why, from overall better hygiene to environmental factors, to modern diets.

One way that experts believe we can combat this rise is through breastfeeding.

“Breastfeeding has been shown in some studies to reduce the risk of allergies, asthma and eczema,” shares Megan Whitacre, APRN, CPNP-PC, IBCLC, a certified pediatric nurse practitioner and international board-certified lactation consultant with ProMedica Women’s Services.

The research is still a work in progress. But we do know that breast milk has an abundance of immunologic benefits, which may contribute to the decreased risk of allergies.

How Breastfeeding Decreases Allergy Risk

Several components of breast milk are likely responsible for decreased allergy risk.

HMOs

Human milk oligosaccharides (HMOs) are complex sugars found only in breast milk. They have prebiotic and antimicrobial benefits, resulting in a stronger gut microbiome.

“HMOs work as bacteria decoys,” Whitacre shares. “Microbes (or germs) attach to HMOs in the gut instead of attaching to gut lining. They are then pooped out by the baby.”

More than 200 different types of HMOs are found in breast milk. “Different women produce different types of HMOs based on their genetics. Breast milk is truly unique and naturally designed to meet your baby’s needs,” Whitacre emphasizes.

Cytokines and Antibodies

Anti-inflammatory cytokines, or small proteins, found in breast milk play a role in the maturation of the immune system. They can induce or suppress immune responses, which may help prevent allergies from developing.

Antibodies found in breast milk create a protective coating on the infant’s gut. This coating prevents allergens and infection from binding to the gut lining.

Anti-Microbial Factors, Proteins and More

Other anti-microbial factors and various proteins in breast milk are thought to help decrease allergy risk. Lactoferrin is one anti-microbial factor that plays a role. It binds to iron, which prevents harmful bacteria from using the iron to grow. Various proteins found in breast milk also help moderate the inflammatory response.

To discover the many components of breast milk and the roles that they play, download this guide. 

Types of Food Allergies

The nine most common food allergies are cow’s milk, soy, egg, wheat, peanuts, tree nuts, fish, shellfish and sesame. Two types of allergic responses exist: IgE mediated food allergies and non-IgE mediated food allergies.

IgE Mediated Food Allergies

IgE mediated food allergies are typically what people think of when they hear the word “allergy.” They create an immune response that usually causes a rapid onset of symptoms when exposed to the allergen. Symptoms typically include rashes, hives, vomiting, wheezing, itching and/or runny nose.

Non-IgE Mediated Food Allergies

Non-IgE mediated food allergies include cow’s milk induced allergic proctocolitis (CMAP) and food protein-induced enterocolitis syndrome (FPIES), celiac disease and eosinophilic esophagitis.

Non-IgE mediated food allergies may not produce immediate symptoms. Typically, they have a delayed affect on the gastrointestinal system. Symptoms may include digestive upset, regurgitation, diarrhea, heartburn and poor weight gain.

With CMAP, the most common symptom is blood in the stool in an otherwise healthy infant. FPIES typically causes gastrointestinal symptoms two to three hours after ingestion. Symptoms may include intense vomiting and diarrhea, leading to weight loss, failure to thrive, dehydration and metabolic imbalances.

“Allergies can be a mix of IgE mediated and non-IgE mediated. So, it can really get tricky! They can affect the entire gastrointestinal tract or just a specific region,” Whitacre explains.

The Importance of Allergen Exposure

“The best way to prevent food allergies is to introduce allergenic foods into the diet early and often. This should start at six months of age, or once the child can chew and swallow,” Whitacre shares.

Breastfed infants can potentially be exposed to allergens that they mother eats even earlier through breast milk. If the proteins of the food are large enough to pass into the breast milk, babies can be exposed.

Allergies While Breastfeeding

A maternal elimination diet is the first line of treatment for an exclusively breastfed baby with a suspected allergy. Skin prick test and blood test are not a reliable method for diagnosing non-IgE mediated allergies.

Start with eliminating cow’s milk because this is the most likely cause. This includes cow’s milk and products containing cow’s milk, such as cheese, butter and ice cream.

Symptoms typically resolve within 72 to 96 hours (although in some cases it can take up to two to three weeks).

If symptoms do not resolve, the mother can add cow’s milk back into her diet and then eliminate the next most likely guess: soy. Continue down the list of common allergens (egg, wheat, peanuts, tree nuts, fish, shellfish and sesame) until the culprit is identified.

Reintroducing Allergens

“At some point, parents will want to try to reintroduce the allergen identified while breastfeeding. This is to decrease the likelihood of it turning into a true IgE mediated allergy,” Whitacre explains. “Parents should follow up with their pediatrician or allergist every one to three months to determine a plan.”

If your child has an allergy to cow’s milk or soy, do not discard any pumped milk with known allergen contamination. Typically, children outgrow this non-IgE mediated food allergy.

Giving them a bottle of allergen-contaminated milk is a great way to see if they still have an intolerance. This allows you to test their tolerance without introducing the allergen back into your diet, as you don’t want to contaminate your milk supply before your baby has outgrown the allergy.

If the baby experiences symptoms, the mother (and baby if started solids) should continue eating a diet free from the allergen. Your pediatrician or allergist can help determine when you should try to introduce the allergen again.