Breastfeeding 101: Elimination Diets For Breastfeeding Mothers

August is National Breastfeeding Month and here at Ready. Set. Food!, we support each and every parent’s decision on how to feed and nourish their families.That’s why we’re proud to join National Breastfeeding Month in helping build a landscape of breastfeeding support with our new Breastfeeding 101 series.

If you think your baby has had an allergic reaction to food proteins in your breastmilk, you'll need to start an elimination diet. Here’s what you need to know about starting an elimination diet while breastfeeding.

For the most part, moms can eat or drink anything while breastfeeding. (There are just a few foods and drinks to be concerned about, as we covered in our previous Breastfeeding 101 post.)

But if your baby has an allergy to a certain food, you'll need to avoid eating that allergen while breastfeeding. This is because the proteins from that food can pass through your breastmilk and cause baby to develop allergic reaction symptoms.

It can be difficult to determine what foods your baby is allergic to when you're breastfeeding, since proteins from all foods can pass through your breastmilk.

So, if you think your baby has had an allergic reaction to food proteins in your breastmilk, you'll need to start an elimination diet.

This diet will help you pinpoint the problem foods that caused the reaction, and figure out what foods you'll need to keep avoiding to keep your baby safe.

Here's what moms need to know about an elimination diet while breastfeeding.

What Is An Elimination Diet?

An elimination diet is a diet where you completely stop eating a specific type of food that you think is causing your baby to develop an allergic reaction (via the proteins passed through your breastmilk).

Why does eliminating foods from your diet help stop allergic reactions?

Normally, proteins from the foods you eat show up in your breastmilk 3-6 hours after you eat them.

If baby has an allergy to any proteins in the foods you eat, their immune system will detect these proteins in your breastmilk.

Their immune system will treat these proteins as foreign invaders, and over-defend the body against the proteins. This causes the body to develop symptoms of an allergic reaction.

(Common allergic reaction symptoms in babies include hives, rashes, vomiting, diarrhea or abnormal stools, congestion, and swelling of the face or tongue. Excessive fussiness and trouble sleeping may come along with the above symptoms, but they are not symptoms of an allergic reaction on their own.)

Starting an elimination diet, where you stop eating foods you think baby is allergic to, ensures that the proteins from these foods won't get passed to baby through your breastmilk. That way, baby won't experience an allergic reaction after they breastfeed.

Learn what is an elimination diet from Nutritionist Dr. Holly Lucille:

Before You Start An Elimination Diet

Before you start an elimination diet, you'll need to figure out what foods you think baby is reacting to, so you can stop eating them.

The best way to do this is to keep a food diary. Log all the foods you eat, along with any possible allergic reaction symptoms that baby develops after you eat those foods.

Look for and note any patterns you see --- for example, does your baby consistently develop diarrhea after you consume cow's milk products? Cow's milk might be the food you'll need to remove.

Then, once you think you've found the foods you should remove, talk to your pediatrician before starting an elimination diet. Bring the results of the food diary.

Usually, a doctor, a dietitian or both will supervise the elimination diet to make sure that you're still eating healthy.

Two Types Of Elimination Diets

There are two ways to start an elimination diet:

Eliminate the suspected allergen (most commonly recommended)

  • Stop eating all food products that contain the suspected allergen.
  • Then, after 1-2 weeks of eliminating the allergen, the proteins from that allergen will stop showing up in your breastmilk.
  • Baby should slowly stop showing allergic reaction symptoms if you've eliminated the right food from your diet.
    • It may take 2-3 weeks for baby's symptoms to fully clear.
  • If baby's symptoms improve after a few weeks, you've found the right food to eliminate, and you should keep eliminating that food from your diet.
  • If baby's symptoms don't improve after a few weeks, you haven't found the right food to eliminate (or you haven't eliminated all the foods you need to). You'll need to try eliminating another food.
    • Talk to your pediatrician before you eliminate the next food (and start the food diary again, if needed).

Follow a low-allergen eating pattern

  • Stop eating several of the most common allergens at once, as directed by your doctor.
    • The foods most likely to cause allergic reactions in babies and young children are cow's milk, egg, peanut, different types of tree nuts (like almond, cashew and walnut), soy, wheat and sesame.
  • Wait 2-4 weeks to see if baby's symptoms improve.
  • If they do improve, one of the foods you eliminated was likely the cause of the symptoms.
    • Add the foods you removed back in, one at a time.
    • Wait at least a week after adding in a food, and see if baby's symptoms re-emerge.
    • If baby's symptoms don't re-emerge, the food you added back in likely isn't the culprit.
    • If baby's symptoms do re-emerge after you add a food back in, you've likely found the problem food. Eliminate that food again and see if symptoms subside. If they do, you've found the food to keep eliminating from your diet.
  • If baby's symptoms don't improve after eliminating several common allergens, another food that you didn't eliminate could be the culprit (or baby's symptoms may not be allergy-related at all). Talk to your pediatrician about next steps.

With any elimination diet, once you've found the food or foods your baby is allergic to, you'll need to stop eating those foods until you are no longer breastfeeding.

Elimination Diet Tips For Moms

  • Your baby could have an allergy to any type of food. But they are most likely to have an allergy to one of the following nine food types, as they represent 90% of all food allergies:
    • Cow’s milk
    • Egg
    • Peanuts
    • Tree nuts
    • Soy
    • Sesame
    • Wheat
    • Finned fish
    • Shellfish
  • Remember that allergens can sometimes show up in unexpected places. So, you'll need to carefully read the labels of foods you purchase, so you don't eat anything that contains the allergen you're eliminating.
    • By law, any food containing the top allergens must be labeled with a clear warning that lists the allergen(s) it contains.
      • For example, a food with cow's milk as an ingredient will have a label that clearly reads "Contains: Milk."
      • Top allergens that must be clearly listed on labels include milk, egg, peanuts, tree nuts, soy, wheat, fish and shellfish.
      • But if you're trying to eliminate sesame, you'll have to be extra careful, as foods containing sesame don't have to be clearly labeled until 2023.
  • Elimination diets don't just involve avoiding foods that contain an allergen. Sometimes, medications and supplements contain common allergens as well. And if a medicine contains the allergen you're excluding, you'll need to avoid it.
    • Carefully check ingredients in your medications and supplements, so you don't accidentally take medicine with an ingredient your baby is allergic to.
  • Keep in mind that your baby could be allergic to more than one food. If this is the case, you'll need to eliminate all baby's allergens from your diet for their symptoms to improve.
    • If baby's symptoms don't improve after you stop eating one food, you'll need to stop eating other suspected allergens as well, until your baby no longer shows signs of an allergic reaction.
    • It will likely take more time to find and eliminate all the foods baby is allergic to from your diet. But the work will be well worth it for relieving baby's symptoms.

Key Takeaways For Moms

If your baby has a food allergy, you can still safely breastfeed. You'll just need to start an elimination diet and stop eating the foods baby is allergic to. With a successful elimination diet, you won't pass the proteins that cause an allergic reaction to your baby, and baby won't experience allergic reaction symptoms.

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All health-related content on this website is for informational purposes only and does not create a doctor-patient relationship. Always seek the advice of your own pediatrician in connection with any questions regarding your baby’s health.

These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure or prevent any disease.  If your infant has severe eczema, check with your infant’s healthcare provider before feeding foods containing ground peanuts.