Did you know that exclusive breastfeeding helps guard against food allergies? Research shows that true allergies from maternal diet in exclusively breastfed infants are rare—only about 1 in 1,000. But those numbers don’t erase the real concerns parents feel when their baby seems uncomfortable or reacts after feedings. This guide aims to help you understand what’s normal, recognize when to be concerned, and find support that brings reassurance and solutions.

How Do Food Sensitivities or Allergies Happen?

It’s important to note that babies are not allergic to human milk itself, but to food proteins that can transfer into breast milk after the mother eats them. In babies with a predisposition to allergies—often due to family history—these proteins can trigger an immune response, causing allergic symptoms such as atopic dermatitis, hives, vomiting, diarrhea, or gastroesophageal reflux.

Common Symptoms to Watch For:

  • Extra fussiness or discomfort, especially during and after feedings
  • New or worsening skin reactions such as hives, atopic dermatitis, or eczema
  • Frequent diarrhea, vomiting, or unusual tummy pain
  • Dirty diapers with mucus or bloody stools

What Should You Do if You Suspect a Food Sensitivity?

If you notice your baby reacting to breast milk, the first step is to consult with their health care provider or pediatric allergist. They can evaluate your baby through medical history, physical exam, and, if needed, allergy testing.

Keep a Food Diary

Tracking foods and symptoms helps identify patterns. Include every meal and note any adverse reactions or changes in your baby's behavior. Review the diary with your healthcare provider to identify the cause of the symptoms and pinpoint potential allergens.

Eliminate Suspected Foods

If an allergen is suspected, the ABM (Academy of Breastfeeding Medicine) recommends continuing breastfeeding while removing the suspected food from the parent’s diet—most often starting with dairy products (cheese, milk, yogurt). Cow’s milk protein allergy is the most common food allergy in infants. Other common allergens include:

  • Egg
  • Peanuts
  • Sesame
  • Fish/Shellfish
  • Soy
  • Tree Nuts
  • Wheat

Pay special attention to packaged products, which can have "hidden sources" of dairy that you may not recognize. This elimination process should be done for at least 2 to 4 weeks, although improvements in symptoms are often seen within 3–4 days.

Reintroduce and Rotate

If the baby's symptoms persist, reintroduce the particular food and eliminate another suspected allergen. Repeat until triggers are identified. An elimination diet, guided by your healthcare professionals, can help manage symptoms while keeping your nutrition balanced. If you need help with meal planning, a registered dietitian nutritionist can help you get the nutrition you need while you are working to find the source of your little one's distress.

According to the ABM, hypoallergenic formula should only be considered in severe cases with impaired growth, decreasing hemoglobin level, or decreasing serum albumin level.

How To Manage Food Sensitivities While Breastfeeding?

Parents should learn to recognize and respond to symptoms of an allergic reaction, including when medications or emergency interventions are needed. Support groups, such as FARE (Food Allergy Research & Education), can offer guidance and reassurance. Thankfully, most food sensitivities or intolerances in breastfed infants are not permanent and resolve naturally by the time most babies reach 9–12 months of age. As the baby's immune system matures, the offending food can usually be reintroduced without the same symptoms returning.

Impact on Mother and Baby

Food intolerances or sensitivities can affect both parent and baby. For the breastfeeding mother, dietary restrictions may lead to nutrient deficiencies if not carefully managed. For babies, ongoing exposure to allergens can contribute to slow weight gain or feeding difficulties. Ensuring a balanced, allergy-free diet supports your health and your baby's growth and development.

Breastfeeding provides your baby with optimal nutrition, immune protection, and comfort while supporting your postpartum recovery. Food sensitivities or elimination diets may be a bump on your journey, but with guidance from your healthcare team, you and your baby can continue breastfeeding safely and confidently.

Disclaimer: Our classes and accompanying materials are intended for general education purposes and should not replace medical advice. For personalized recommendations, please consult your healthcare provider and/or lactation consultant.