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How to Prevent Food Allergies in Infants: A Guide to Early Allergen Introduction

Babies are wonderful… and feeding them is sometimes stressful. Food allergies are just one of many things you have to think about. While food allergies can sound scary, there’s actually something you can do to help stop your child from getting them. As your baby grows out of the newborn stage, they approach a big milestone: introducing complementary foods, including the common allergens. Key takeaways in this section…

  • Offer baby-friendly foods, in addition to their usual breastmilk/formula diet. These foods are called “complementary foods.”
  • After giving a few starter complementary foods, begin adding in the common allergens.
  • Offering allergens early — and keeping them in the diet — can help stop your baby from developing food allergies as they get older.
A baby wearing a pink bib sits in a high chair while an adult feeds them with an orange spoon. The baby looks forward with their mouth open, ready to eat.

Research shows that giving food allergens to your baby early — around 6 months old, and even as early as 4 to 6 months — and continuing to offer them regularly, can lower the risk of your child getting a food allergy later in life.

Following the same thought, waiting to give food allergens until your baby is older may increase their chances of developing a food allergy.

So, how do you begin introducing allergens to your baby? Good question. The following guide can help.

  • alert iconThis guide is here to support you with easy-to-understand, medically reviewed food allergy and anaphylaxis information you can trust. Use this as a resource as you prepare to talk with your child’s healthcare team.

Step-by-step introduction

Introducing food allergens doesn’t have to be hard. In fact, you can introduce them at the same time you start to offer other solid foods to your baby. These foods together are all called “complementary foods,” because you are giving them while still feeding your baby mainly through breastmilk or formula. With the right steps, you can safely add them to your baby’s diet and help prevent food allergies.

First things first! Start when your baby is developmentally ready to eat solid foods. This is usually around 6 months old, but can be as early as 4 months. What does “developmentally ready” mean? The common signs in babies are:

  • Sitting with only a little support
  • Controlling their head and neck
  • Bringing objects to their mouths
  • Opening their mouth when food is offered
  • Trying to grasp small objects
  • Swallowing food instead of pushing it out with their tongue

Some infants may show developmental signs of readiness before age 6 months. Does this mean you can introduce complementary foods earlier? It depends. Introducing complementary foods before age 4 months is not recommended. Neither is waiting until after 6 months.

If you’re unsure, you can talk to your healthcare team at any of your baby’s first appointments.

Okay, your baby is the right age and has shown they are developmentally ready to try solids. Time to start thinking about foods! There are a lot of options for your baby’s first complementary foods. Pick a couple of common ones to start before trying the food allergens. Some great first choices for complementary foods could be infant cereal (like oatmeal) or applesauce, or pureed sweet potato, avocado, banana, carrots, or meats (like chicken or beef). Your baby’s first foods should be very soft or pureed.  

When considering what foods to give, also keep in mind the foods to avoid:

  • Cow’s milk as a drink shouldn’t be introduced until age 1.
  • The same goes for honey — none before age 1.
  • Loose nuts and seeds can be a choking risk. Wait until around age 5 for these. Also be careful with clumps or chunks of nut butters.
  • Avoid high-mercury fish, like swordfish and some types of tuna. Fish like cod, tilapia, salmon, and flounder are better choices.
  • Also avoid raw seafood, raw meats, and unpasteurized dairy that can cause foodborne illnesses.
  • Limit added salt and sugar. *

Once your baby is eating and enjoying a few foods, the next step is to introduce the foods that can possibly cause allergies.

The following top food allergens should be introduced early in baby-friendly forms and kept in your baby’s diet regularly:

  1. Peanut
  2. Eggs
  3. Cow’s milk products 
  4. Tree nuts
  5. Sesame seeds
  6. Fish
  7. Shellfish
  8. Wheat
  9. Soy

*Note: Though limiting added salt and sugar is a great thing you can do for your baby’s health, introducing allergens to your baby is very important. For example, if the only peanut butter you can find is regular peanut butter, and not one with no added salt and sugar, don’t worry! Peanut butter is a great way to introduce peanut to your baby, and the best peanut butter is always the one you can easily buy and give regularly.

When picking and preparing those first food allergens, we talk a lot about “baby-friendly forms”. What do we mean by that? We mean making sure to give allergenic foods in a way that’s safe and easy to swallow. You can puree many foods by mashing or blending them into a smooth and even texture. This will help prevent choking while they are learning how to chew and swallow. Here are some examples:

  • Eggs: Start with well-cooked eggs, such as scrambled. Mash or blend both the white and yolk. Eggs are a great first food to try with your baby.
  • Cow’s Milk Products: You can introduce dairy in baby-friendly forms, like plain whole milk yogurt or soft, pasteurized cheese, including ricotta, mozzarella, or cottage cheese. Plain whole milk yogurt is another great first food to offer your baby.
  • Peanut and tree nuts: Whole nuts or thick spoonfuls of nut butter can be choking hazards for babies. It’s much safer to use smooth nut butters (not crunchy) and always thin them (such as with water, breast milk, formula, or pureed foods your baby has already tried and eaten without problem). Nut butters should be runny, not sticky. You can also use nut powders stirred into baby cereal or purees.
  • Wheat: Often introduced through fortified infant wheat cereal, tender-cooked pieces of pasta, or strips of whole wheat toast. Make sure foods are soft and easy to swallow.
  • Soy: Soy can be introduced in forms like tofu, soy yogurt, or soy flour in baked goods. Avoid highly salty options like soy sauce. Start with soft, plain versions that are easy to mash.
  • Sesame: Use tahini (sesame paste) and mix it into a familiar puree or thin it out with water, breast milk, or formula before serving.
  • Fish and shellfish: These should be fully cooked, boneless, and mashed or flaked to reduce choke risk.

As a more detailed example, let’s take a look at preparing peanut. 

Peanut butter is not only an easy, go-to food, but it is also an excellent source of protein, fat, and other essential nutrients. Peanut butter is thick and sticky right out of the jar, and by itself can be a choking hazard for a baby. To safely serve smooth peanut butter (not chunky!), simply thin it out by using breast milk, formula, plain water, or a pureed food your baby has already tried and tolerated.

Let’s look at how to thin peanut butter in 3 easy steps:

  1. Start by taking 3 teaspoons of pureed fruit and place it into a bowl. 
  2. Next, measure 2 leveled teaspoons of peanut butter and add it to the fruit puree.
  3. Use a small whisk or fork to blend while mashing the peanut butter against the side of the bowl. Keep in mind that this process can take several minutes until the peanut butter and fruit puree are fully combined.

Once the peanut butter is thinned, it’s time to start eating. Slowly feed your baby a small amount on the tip of a spoon and wait about 10 to 15 minutes for any reaction. If there are no signs of a reaction, and your baby seems to enjoy the food, you can continue feeding.

You can also use this thinning method for other nut butters, such as almond or cashew, and seed butter or pastes like sesame tahini and sunflower seed butter, which are also full of nutrients. 

By this stage, your baby’s first taste of food allergens is underway. We hope they enjoy trying mashed eggs, plain whole yogurt, and thinned peanut butter. In the early days of introducing food allergens, don’t worry if your baby isn’t reaching the goal amount right off the bat. The key here is to add each new allergen one at a time — say, every few days — and keep it in the diet as part of your baby’s weekly routine. You may need to gradually increase how much of the allergen they eat over the course of several weeks.

As you learn more about introducing allergens, you may hear different advice on how long to wait between each one. Some might say you can offer a new allergen every day, while others may say every couple of days. Some might say every few days. Don’t worry! As long as you are introducing all the allergens between 4-6 months, the pace doesn’t matter as much. However, if introducing a new allergen every few days means you are still introducing new allergens at 7, 8, or 9 months, think about how to change your plan. In the end, do what works best for you and your baby.

Your baby may not always want to follow a set plan, and that’s okay! Some days your baby may not want to eat a new food, and you have to try again the next day. Some days your baby may want to eat less, and some days more. While we aim for certain goals with each allergen, you know your baby and what they can do best. Don’t give up if they are not eating everything you make every single time. This is normal, and it’s important to keep trying. Keep offering those allergenic foods!

Note: It can be hard to tell how much of each allergen your baby is eating and how close they are to the actual goal. The best you can do is aim for reasonable targets and be as consistent as possible. For example…

  • Peanut: Around 2 teaspoons, 3 times a week.
  • Tree Nuts and Sesame/Tahini: About 2 teaspoons, 2 times a week is a great target.
  • Cow’s Milk Products: For plain whole milk yogurt, gradually increase to a goal of 2 ounces (4 tablespoons), at least 2-3 times a week.
  • Eggs: Try for 1/3 of a large egg at least twice a week.
  • Fish and shellfish: Fish and shellfish can be harder to keep in the diet, so aim for once every couple of weeks. A good serving is the size of your baby’s palm, in baby-friendly forms.

Now that you’re successfully introducing the food allergens, you can focus on keeping them in the diet as part of your baby’s weekly routine as you work towards goal amounts. A great way to do this is to mix the food allergens together with already tolerated foods. Having these foods in the diet over and over again is what will help your baby tolerate them throughout their childhood and as adults.

Keeping all of these foods in your baby’s diet can feel like a lot – especially if you have to do this 2 to 3 times per week. What’s something you can try? Mix and blend these foods into familiar meals, like nut butter in oatmeal or egg in muffins. Or combine already tolerated allergenic foods when possible.

For example:

  • Stir peanut powder into yogurt
  • Bake muffins made with egg, nut butter, and milk
  • Make purees with mashed fish, tofu, and vegetables

As your baby moves from purées to eating more family meals, it’s important to keep including the allergenic foods they’ve already tried. Some tips for helping with this:

  • Add allergenic ingredients into soft, age-appropriate family meals (like egg in pasta or peanut butter in smoothies).
  • Watch for choking hazards as textures get more solid – mash, chop, or blend as needed.
  • Continue offering these foods a few times per week to support tolerance.

This phase is a great opportunity to help your child explore new flavors and textures, and keep up allergy prevention as they eat more and more foods. Side benefit: you’re not always making separate meals for your baby!

Key takeaways

Knowing all the steps for introducing food allergens to your baby is important, but it can also feel like a lot. Here are some key points to take special note of:

  • Pay attention to timing – Start offering food allergens to your baby around 6 months, and even as early as 4 to 6 months, if they are developmentally ready (see Step 1, above). This will be around when other complementary foods are introduced.
  • Avoid choke risks – Baby’s first foods should always be in baby-friendly forms, like pureed! (See step 3).
  • Be consistent – In the beginning, your baby may not be eating all of the allergen you prepare. As long as they are making some progress, that’s a great start! The key is to be consistent about feeding every week and to try to increase the amount they eat over time to reach the target goal (see Step 4).
  • Offer a diet with lots of variety – While you don’t want to offer two new foods in the same meal, giving your baby a chance to try lots of different foods over time is great. They get to experience lots of different flavors and textures, and they get what they need to grow and thrive. Variety is the spice of life!
  • Keep your healthcare team in the loop – They are here to support you! Let them know how things are going with plans for feeding, and reach out as soon as questions come up. Sometimes it can be hard to get a timely appointment, so talk to your healthcare team as early as possible. For instance, it’s better to get answers at a 1 – or 3-month appointment rather than at a 6-month appointment.
early introduction reduces the risk of developing a food allergy
delayed introduction increases the risk of developing a food allergy

Other things to think about

Besides the when and how of introducing foods, there are some other things to pay attention to when it comes to food allergies.

It’s also important to pay attention to your baby’s skin. While your baby is not yet getting introduced to new foods to eat, they may still be coming into direct contact with specific food allergens on their skin. If this happens regularly, it may increase their chances of developing an allergy to that particular food. This is especially important for babies with inflamed or irritated skin, like with eczema. Studies show that while eating an allergen early can protect your baby from that food allergy, routine contact with the skin puts them at higher risk.

So what can you do to help protect your baby’s skin? Our suggestion: wash hands after eating, especially if the food eaten is a common allergen, and before handling baby’s skin, like with diaper changes and applying lotions and creams. If you think your baby has signs of eczema, talk to your healthcare team about skin management and developing a plan for introducing food allergens early.

Babies with eczema have a higher chance of developing a food allergy. This is especially true if there is a delay in introducing allergens, or with increasing eczema severity (mild –> moderate –> severe), so speak to your healthcare team as early as possible about what the plan will be for introducing food allergens. Current recommendations suggest that once cleared by your healthcare team and as soon as your baby is developmentally ready, you should give them baby-friendly forms of food allergens. This can be as early as 4 months.

While we mentioned that some babies show signs of developmental readiness before 6 months, the opposite can happen, too. Some babies may take a little longer to be ready, and that’s okay. Let the developmental signs of readiness be your guide. During this time, be sure to pay attention to your baby’s skin, as noted above.

When you first start feeding your baby solids, you may be worried about allergic reactions. Severe allergic reactions are not common in babies. In most cases, symptoms will be mild. Your baby can’t tell you what they are feeling with words, but there are some signs that let us know that they may be allergic to a food.

These signs may include:

  • A quickly appearing rash, like hives (red, itchy bumps)
  • Vomiting
  • A change in behavior soon after eating, like suddenly becoming fussy
  • Coughing, sneezing, or a sudden increase in drooling can also occur in combination with other symptoms.

If one or more of these signs occur soon after adding a new food, stop feeding your infant, watch them, and if you have any concerns, call your healthcare team.

Babies rarely have a severe reaction. But if they do, it may look something like this: 

  • Hives spreading to cover the entire body
  • A lot of swelling of the lips, face, or tongue
  • Perhaps some difficulty breathing or repetitive vomiting/diarrhea. 
  • Repetitive coughing, changes in skin color, sudden tiredness, or going limp.

If you notice any of these more serious signs of an allergic reaction, get immediate medical care. Call 911.

If your child does get diagnosed with or already has a food allergy, make sure to check out this page of signs and symptoms for a more detailed look at what to do during an allergic reaction.

Your child may also have a different type of food allergy, called non-IgE-mediated (example: FPIES), which can sometimes have similar symptoms. For example, children with FPIES can have vomiting, but it’s usually delayed from when they eat the food. Check out the page Understanding and Diagnosing Food Allergies in Infants & Toddlers for more on non-IgE-mediated food allergies.

If you’re saying to yourself, “Pump the brakes! I’ve just had my baby!” then don’t worry, you’re getting this information nice and early. While it’s never too soon to start planning when and how you’ll introduce food allergens to your baby, there’s plenty you can do now if you’re a breastfeeding mom. If you can and are breastfeeding, keep in mind that what you eat affects your breastmilk and your breastmilk is what feeds your baby! When choosing meals and snacks, pick a variety of healthy foods loaded with vitamins and minerals, as well as protein. Think: colorful fruits and veggies, healthy fats, and whole grains. Choose protein from meats; poultry; eggs; dairy; legumes like beans, lentils, and peas; nuts and seeds; and low-mercury seafood like salmon, cod, and shellfish. As much as possible, avoid highly processed foods with lots of added salt and sugar. Filling yourself up on nourishing foods can boost your breast milk with essential nutrients to grow a healthy baby.

If you are not allergic to the common food allergens, there’s no reason to avoid them while breastfeeding. They are rich in nutrients and should be included in a healthy, well-rounded diet. It may also be nice to hear that research suggests a diverse diet with a wide variety of nutritious foods may also help lower the risk of food allergies.

Resources for families

3-video series on Early Introduction:

One-page handout outlining the basics of early introduction, for easy reference:

FAMPIT Early Intro one page handoutDownload

Guidelines and recommendations for early allergen introduction

As new research comes out, guidelines and recommendations get updated to give families and their healthcare teams the best advice available. For those who love to deep dive into the science, see the below links to some of the most used and up-to-date guidance on food allergy prevention.

A Consensus Approach to the Primary Prevention of Food Allergy Through Nutrition: Guidance from the American Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; and the Canadian Society for Allergy and Clinical Immunology

2025-2030

2020-2025

Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases–sponsored expert panel

Messy but happy baby in a high chair with an illustrated hand and spoon offering food.

Questions & answers (Q&A) on early allergen introduction

Early allergen introduction can feel overwhelming for many parents and caregivers. Here are answers to common questions we’re asked about preventing food allergies and early allergen introduction.

Early in life, your baby is probably going to have a lot of appointments to go to. It’s common to have check-ups every few months. Your baby is growing so fast during this time, and there is a lot to talk about with your healthcare team. It can feel challenging to fit everything in!

If you have questions about early introduction, you can ask them at any appointment. The best time to bring up complementary foods and food allergens is before the 6-month appointment, even if your baby is not showing signs of being ready. Your healthcare team can help you feel more confident in offering your baby solid foods and food allergens.

Here are some questions you can ask your healthcare team leading up to, and during, those early appointments:

  • What should my baby be doing that shows they are ready to start trying solids?
  • A family member has a food allergy. What should I do when it comes to offering allergens to my baby?
  • My baby had a little bit of mashed banana and got a bit of redness on the face. I took a picture. Is this an allergic reaction?
  • My baby has an itchy rash on their elbows and arms. I took a picture on a day it seemed really bad. What is it? What does this mean for food introduction?

Yes, research shows that introducing allergenic foods early can lower the risk of developing food allergies. 

Studies found that babies who regularly ate foods that contain peanuts (in a puree) or eggs starting at 4 to 6 months were less likely to develop allergies. These findings helped change medical guidelines.

Today, doctors recommend early allergen introduction for all babies, not just those at high risk for food allergies.

Interested in doing a deep dive into the research behind Early Introduction? Check out these studies to learn more:

Introducing solid foods before 4 months of age isn’t recommended because a baby’s digestive system may not be ready. Starting too early can increase the risk of choking or feeding difficulties, but it does not cause food allergies.

In fact, current research shows the opposite: introducing allergenic foods like peanut and egg around 4 to 6 months, when your baby is ready, can actually help prevent food allergies. This shift in thinking is based on strong evidence from recent studies like LEAP and PETIT.

You can start offering new foods around 6 months, and even as early as 4 to 6 months, introducing one new food at a time. This should include allergenic foods. If your child has eczema, talk to your healthcare team about a plan for introducing allergenic foods.

There’s no way to change “allergy levels” in the blood. Instead, early and regular exposure to allergenic foods may help prevent food allergies from developing. For babies with diagnosed allergies, talk to your doctor about testing or treatment options and how to manage allergies.