Can Your Baby Be Allergic to Your Breast Milk?

There’s a reason breast milk is considered the best source of food for your baby. It provides your little one with all the nutrients and calories needed for their health. In fact, breast milk has so many benefits that the American Academy of Pediatrics (AAP) recommends breastfeeding for two years or longer.

“We know that breastfeeding provides optimal nutrition for babies, and a host of other benefits for parents and babies alike,” says pediatric allergist Jackie Bjelac, MD.

We also know it isn’t always easy. Breastfeeding (chestfeeding) can be time-consuming. It can be physically taxing. And it can make you wonder what kinds of food you should eat or avoid while breastfeeding and how those foods will affect your child.

With all the talk about food allergies in kids on the rise, you may wonder how that impacts your breastfeeding diet. For instance, should you avoid familiar allergens like peanuts or eggs, lest they transfer through your breast milk? Can babies have an allergic reaction to the breast milk you’re feeding them? Or is your baby’s crying, excessive gas and diarrhea a sign of nothing more than food intolerance? What is the difference — and does it matter?

Dr. Bjelac explains how your baby might develop food intolerances to some of the foods you eat while you’re breastfeeding and why this is often not an emergency but a manageable condition.

Newborn allergies vs. food intolerance and sensitivity

There’s often much confusion around food intolerances and food allergies. Whereas food allergies are an immune system attack and are much more severe, food intolerances (also known as food sensitivities) are digestive concerns that happen because your baby’s little body has a difficult time breaking down the proteins in a particular food.

Symptoms of food intolerances are gastrointestinal and include symptoms like:

• Excessive crying.
• Diarrhea, sometimes with blood in the stool (poop).
• Spitting up.
• Gassiness.
• Bloating.
• Stomachache.

According to the AAP, only 2 to 3 babies out of every 100 infants experience symptoms related to a food intolerance. When these symptoms occur, it’s because trace amounts of microscopic food proteins leftover from the foods you’ve eaten can sometimes slip through into your breast milk.

“For that 2% to 3% of babies who do have this milk protein intolerance, there are two solutions,” shares Dr. Bjelac. “The breastfeeding parent needs to avoid milk in their own diet so the baby doesn’t see any of that protein through their milk. Or if they don’t want to breastfeed or can’t maintain a supply without consuming cow’s milk, then the baby needs what’s called a hypoallergenic formula where the milk proteins are actually broken down so they don’t look like milk to the gut anymore.”

The reason it’s so important to specify these symptoms are related to intolerances and NOT allergic reactions is because allergic reactions on their own can bring about much more serious symptoms — and it’s extremely rare, if not impossible, for a baby to experience an allergic reaction to breast milk.

Milk allergy in infants

Cow’s milk is the most common food allergy in kids, but it’s not something that can slip through into breast milk and cause an allergic reaction.

“Babies are not allergic to breast milk,” clarifies Dr. Bjelac. “Very little food protein is passed through breast milk directly to the baby, so the chances that your baby will have a true allergic reaction to something you eat is very, very small.”

In fact, a recent study found that less than 1 in 1,000 breastfeeding parents have detectable amounts of cow’s milk proteins in their breast milk that could even cause an allergic reaction in breastfed babies. So, the probability of a serious allergic reaction, or anaphylaxis, happening is far too low to be considered likely.

“Most of us in the medical community think that it’s virtually impossible for a baby to have anaphylaxis to proteins in breast milk,” explains Dr. Bjelac. “There’s just not enough food proteins in breast milk to cause such a reaction. But there is enough to cause gut issues.”

If your child is allergic to cow’s milk, for them to experience symptoms of an allergic reaction, they would have to drink cow’s milk on their own.

“A child needs milk exposure to cause allergic symptoms,” she continues. “If you’re a year old and you drink milk formula for the first time and you immediately break out in hives, vomit and have trouble breathing — that’s an allergy. That’s an immune system problem. But even if that child is milk-allergic, there’s not enough milk protein in mom’s breast milk to cause those types of symptoms.”

Symptoms of dairy allergy in breastfed babies

Remember: It’s highly unlikely for breastfed babies to have an allergic reaction to cow’s milk unless they were to drink it on their own outside of breastfeeding. If your child has a milk allergy, drinking cow’s milk on their own can cause a wide range of symptoms that can get worse with each exposure to cow’s milk. Some of the most common symptoms of an allergic reaction include:

• Hives or skin rash.
• Nausea or vomiting.
• Abdominal pain.
• Swelling of the face, lips tongue or throat.
• Dizziness.
• Shortness of breath.
• Difficulty swallowing.
• Coughing or wheezing that lingers for several hours after drinking milk.

When an allergic reaction in babies is an emergency

If your child has difficulty breathing, breaks out in hives or a rash, or experiences swelling, vomiting, wheezing or dizziness, call your pediatrician right away. Allergic reactions may be rare but when they happen, fast action is key to stopping them in their tracks because they can be severe and sometimes even fatal.

How to deal with milk protein intolerances

Don’t go cutting foods out of your diet until you talk with your healthcare provider first. While food intolerances can result in late-night crying and gastrointestinal upset, research suggests doing a food elimination diet or cutting out foods can actually cause more harmful adverse effects than providing benefits for your child. Plus, elimination diets should only be followed when prescribed by a healthcare provider, especially because they may cause nutritional imbalances that then lead to a low milk supply.

“What’s important when you’re breastfeeding is having a well-rounded diet so you can continue to produce enough milk and breastfeed as long as you wish to,” Dr. Bjelac says. “If you start cutting out a lot of foods, your nutrition can start to suffer, and then, supply becomes an issue. It’s hard to successfully breastfeed on a restricted diet, so we never want you to cut foods out unnecessarily.”

Plus, studies have shown that breast milk is not only key to building your baby’s immune system, but it could also help prevent future allergies by introducing kids to certain allergens earlier on. A new analysis of 4,015 articles and 32 systematic reviews found that allergenic foods should be introduced to a child’s diet before 11 months to prevent the development of further allergies.

“The guidelines from the AAP are to introduce some common food allergens, like peanuts, eggs, soy and wheat, when your baby is around 6 months old,” she adds. “It’s when your baby tries foods for themselves that you’ll want to monitor them for signs of an allergic reaction, like swelling or hives.”

While the AAP recommends saving cow’s milk after your baby hits their first birthday, products like whole-milk yogurt and cheese can be given to babies around 6 months old. And if your baby does have an allergic reaction, that’s when you want to get them medical attention and work with your healthcare provider on whether or not it’s worth removing certain foods from your and their diet.

In the instances of food intolerances, when babies have a hard time digesting certain food proteins, they may benefit from you cutting back or cutting out the offending foods entirely.

“The amount of protein it takes to trigger digestion problems from a food intolerance is very small — much less than it would take to trigger an allergic reaction,” Dr. Bjelac explains. “So, babies who have an intolerance can benefit from alterations to your diet.”

If your healthcare provider suggests cutting out cow’s milk, for example, you’ll likely want to cut out milk from other mammals, too, like goat’s milk and sheep’s milk. Other milks like coconut milk and almond milk won’t need to be avoided in most cases.

“With milk protein intolerances, babies can be spitty, fussy and have bloody stools or gnarly poops, but those symptoms get better when mom avoids milk,” notes Dr. Bjelac. “Additionally, many kids outgrow milk intolerance by their first birthday, and 95% of kids have outgrown it by 2 or 3 years of age.”

Bottom line?

At the end of the day, if you’re concerned about food allergies or intolerance, don’t hesitate to reach out to a healthcare provider.

Working with a lactation consultant can also be helpful in figuring out what’s working and what’s not when it comes to feeding your baby and keeping them safe.

If at any point you choose to stop breastfeeding and need to supplement formula, you can always get help with relactation down the line when or if you’re ready to breastfeed again.

“Some babies are fussy. Sometimes, babies are gassy. Sometimes, babies cry,” Dr. Bjelac says. “Not everything is related to what they’re eating and very unlikely related to what the breastfeeding parent is eating. But getting a doctor’s opinion can give you some peace of mind and tools to help your baby be their best and thrive.”