What is Early Allergen Introduction? How to Introduce Allergens to Baby?

What is early allergen introduction? Today, we’re covering the most up-to-date information on early food allergen introduction so you can make informed decisions for your family. Learn about the studies and medical guidelines that support early allergen introduction, and how to safely introduce common allergens to your baby.

Food allergies affect over 30 million Americans, including 1 in 13 children. Babies aren’t born with food allergies – rather, food allergies develop over time. And all babies are at risk for food allergies, regardless of their family allergy history.

Anyone can develop a food allergy at any time. And when someone with a food allergy eats even a small amount of the food they’re allergic to, their body will develop an allergic reaction that could potentially be severe or even life-threatening. 

Today, we’re covering the most up-to-date information on early food allergen introduction so you can make informed decisions for your family. What is early allergen introduction, why is it important, and how to do it safely? Learn about the studies and medical guidelines that support early allergen introduction, and how to safely introduce common allergens to your baby.

What is early allergen introduction?

Early allergen introduction involves feeding your baby allergens early and often, starting during their first year of life.

This means consistently feeding babies the foods responsible for the most common childhood food allergies. 

What allergens should baby be introduced to?

You should introduce baby to the following foods, as 90% of food allergies in children are to these foods:

  • Peanut
  • Egg
  • Cow’s milk
  • Tree nuts (such as almonds, cashews, and walnuts)
  • Wheat
  • Soy
  • Sesame

Peanut, egg, and milk alone account for around 80% of food allergies in the youngest children.

Why is early allergen introduction important?

1 in 13 children has a food allergy, but babies aren’t born with food allergies – they develop over time. And all babies are at risk for food allergies, even if none of their direct family members has an allergy.

Landmark clinical studies, and several sets of recent medical guidelines, recommend early allergen introduction to promote a healthy future of food freedom.

Previously, it was thought that waiting to introduce allergens for 1-3 years was the best approach. But this wasn’t backed by science.

Thanks to the recent studies and guidelines, we now know that the opposite is true – to promote healthier outcomes later in life, introducing allergens during baby’s first year is a much better approach than delaying allergen feeding.

When to start early allergen introduction?

The best time to start introducing common allergens is when baby is between 4 and 6 months of age. Recent findings from the landmark LEAP and EAT trials have shown that starting peanut introduction at 4 months of age (and before 6 months of age) is best for healthier outcomes. Introducing peanut in this window can help your child’s body be more likely to recognize peanut as just food. 

The results also showed that the impact of early allergen introduction decreases as the age of introduction increases. In other words, the earlier you start feeding common allergens, the more likely your child will be able to freely eat those foods later in life. And it’s important to introduce all infants to peanut before 6 months of age, not just infants at higher risk of peanut allergy. 

In addition, guidelines from the American Academy of Allergy, Asthma, and Immunology (AAAAI) recommend that “both peanut and egg should be introduced around 6 months of life, but not before 4 months.”

But if baby is older than 6 months of age, it's still not too late to introduce allergens (assuming they don't already have an allergy to a given food). As landmark studies and guidelines have shown, starting as soon as you can is a much better approach than delaying allergen feeding for 1-3 years. 

What landmark studies changed the way we think about introducing allergens?

Three recent studies have changed the way we think about introducing allergens.

These studies show that babies should start consuming foods like peanut and egg in their first year of life.

  1. LEAP Trial (Learning Early About Peanut Allergy)
  • 600 babies, ages 4-11 months, participated
  • All were at higher risk for peanut allergy
  • Were randomly assigned to consume peanut regularly (at least 3 times a week) until age 5 or avoid peanut completely until age 5
  1. EAT Trial
  • 1,300 babies, all 3 months old, participated
  • None were at increased risk for food allergies
  • Were randomly assigned to consume six different foods (peanut, egg, milk, wheat, sesame, whitefish) consistently for 3-6 months, or completely avoid all of those foods for at least 6 months
  1. PETIT Trial
  • 147 babies, all 4-5 months old, participated
  • All were at higher risk for egg allergy
  • Were randomly assigned to consume egg daily, or avoid egg completely, for 6 months

All three of these studies’ results showed that early allergen introduction – consuming the foods early – led to healthier outcomes for children later in life. More of the children in the early introduction groups were able to freely eat the foods involved in their respective studies later in life, because their bodies were primed to recognize these foods as just foods.

The results of these studies have inspired (and supported) several sets of important clinical guidelines around the world, which all recommend early allergen introduction. We’ll cover some of the most recent and notable guidelines below.

What do the new medical guidelines say about early allergen introduction?

Two important sets of clinical guidelines on early allergen introduction come from the U.S. Department of Agriculture (USDA) and the American Academy of Allergy, Asthma, and Immunology (AAAAI).

USDA Dietary Guidelines

The most recent USDA dietary guidelines recommend feeding foods like peanut and egg early, within baby’s first year of life.

As the guidelines state, “It is important to introduce potentially allergenic foods along with other complementary foods…Potentially allergenic foods (e.g., peanuts, egg, cow milk products, tree nuts, wheat, crustacean shellfish, fish, and soy) should be introduced when other complementary foods are introduced to an infant’s diet.”

The guidelines put special emphasis on “introducing peanut-containing foods in the first year.” And if a baby is at higher risk for peanut allergy, the guidelines state that “peanut-containing foods should be introduced into the diet as early as age 4 to 6 months.”

AAAAI Guidelines

The AAAAI guidelines focus most on early peanut and egg introduction. These guidelines recommend that “both peanut and egg should be introduced around 6 months of life, but not before 4 months.”

The AAAAI guidelines also recognize that consistently feeding peanut and egg is best for promoting healthier outcomes, as demonstrated by the LEAP, EAT, and PETIT studies. Based on the amount of peanut used in the LEAP study, and the number of times it was given in a week during the study, the AAAAI recommends feeding baby 2 grams of peanut protein at least three times per week.

But the guidelines don’t stop there. They also state that “Other allergens should be introduced around [4-6 months of age] as well,” and tell parents and caregivers, “Do not deliberately delay the introduction of other potentially allergenic... foods."

Thus, the guidelines emphasize that babies should consume several other common allergens, including cow's milk, soy, wheat, tree nuts, and sesame, early.

What other research supports early allergen introduction?

Since the three landmark studies were published, even more research has emerged that supports early allergen introduction. Here are some of the most notable findings:

1. EarlyNuts Study (2018-2019 cohort)

  • 1,933 infants participated
  • All turned 12 months old between 2018 and 2019
  • Study examined early peanut introduction at home
  • Cross-section of the population, so not all children in the study were at high risk of peanut allergy
  • The group of infants that started eating peanut before 12 months of age had healthier outcomes than the group that wasn't introduced to peanut in their first year

2. LEAP and EAT Studies (new findings in 2022)

  • Researchers from the LEAP and EAT trials re-examined data from the children who participated in these studies
  • They found that the earlier peanut was introduced, the more likely a child's body was to recognize peanut as just a food
  • They also found that the best time to introduce peanut is at 4 months of age, for all babies (not just those at high risk of peanut allergy)
  • According to the new results, introducing peanut at 4 months of age leads to healthier outcomes than introducing it at 6 months of age
  • And introducing peanut starting before 12 months of age leads to healthier outcomes than introducing it at 12 months of age
  • These studies involved consistent introduction, so frequent feeding of peanut was also key to these healthier outcomes

Is early allergen introduction safe?

As long as you feed your little one baby-safe forms of each allergen, it’s safe to introduce all of these allergens to your baby during their first year.

In fact, a study has shown that before age 1 is the safest time to introduce allergens, because severe allergic reactions are least common in babies younger than 1 year old.

And since allergic reactions tend to get more severe as a child gets older, that’s another reason why starting as early as possible is safest for introducing these foods.

As Dr. Jonathan Spergel (Head of Allergy at Children’s Hospital of Philadelphia, and one of the study’s authors) shared, "Babies have the fewest severe allergic reactions of any age group, with the severity of allergic reactions increasing as the child gets older. No food allergy deaths have been reported in infants under age 1.”

How to introduce allergens to baby?

Before introducing a common allergen food for the first time, make sure your baby is healthy. This way, it will be easier to tell how baby responds to the food. Also, make sure that you can watch baby closely for at least 2 hours, in case they would develop symptoms of an allergic reaction. 

Although you could start feeding common allergens in any order, we recommend starting with milk, egg, and peanut, because these foods account for the most food allergies in young children.

Once you've started to introduce allergens, it's important to keep feeding baby those allergens regularly in their diet. Regular feeding means giving your baby these foods multiple times a week for several months.

Feeding baby a diverse diet, where they eat common allergen foods often, primes baby’s body for a future where they can eat these foods throughout the rest of their life.

Below, we'll go over ways to safely feed baby four of the most common types of allergens (peanuts, tree nuts, milk, and eggs).

How can I safely introduce peanut and tree nuts to my baby?

Never feed whole peanuts or any chunky peanut butter to your baby. Also, never feed baby smooth peanut butter that isn’t watered down. These are all unsafe to feed any child under 4 years of age, because they are choking hazards.

“Whole-peanut kernels and chunks of peanut butter are potential choking hazards and should not be given to children younger than 4 years.” – AAAAI guidelines

As chunky peanut butter contains hard peanut pieces, the choking dangers it poses is obvious. But even smooth peanut butter offered by itself can pose a choking hazard to young children.

That’s why the National Institute of Allergy and Infectious Diseases (NIAID) states in their own peanut feeding guidelines, “Peanut butter directly from a spoon or in lumps/dollops should not be given to children less than 4 years of age.”

Fortunately, there are several baby-safe ways to introduce peanut to your little one.

The AAAAI recommends these safe ways to introduce peanut in the first year:

  • Peanut flour, mixed with baby’s puree or another food
  • Peanut powder, mixed with baby’s puree or another food
  • Diluted smooth peanut butter (watered down and thinned)

Take a similar approach to introducing different types of tree nuts, to avoid choking hazards. Never feed baby whole tree nuts, chunky tree nut butters, or smooth tree nut butters that haven’t been diluted. Instead, use tree nut flours, tree nut powders mixed with baby’s food, or watered down smooth tree nut butters.

Is it safe to feed baby cow’s milk before their first birthday?

You should not offer cow’s milk as a drink until baby reaches their first birthday. The American Academy of Pediatrics (AAP) advises that you shouldn’t give cow’s milk as a drink during their first year, as cow’s milk can’t replace the nutritional value of breastmilk or formula.

However, it’s perfectly fine to introduce cow’s milk in other ways – as a supplementary food, not a drink – before age one.

Some baby-safe ways to introduce cow’s milk include plain yogurt, whole-milk cheese, or milk powder mixed with baby’s food.

How can I safely and successfully introduce egg to my baby?

For baby’s safety, make sure that any egg you feed baby is well-cooked. You can offer cooked egg powder mixed in with baby’s puree, oatmeal, or other food. You can also include egg into healthy baked goods, such as veggie muffins. Scrambled egg pieces are another option, but many younger babies have trouble with scrambled eggs. In most cases, egg powder is your best bet for egg introduction.

How to easily introduce allergens into baby’s diet?

Little ones can be picky eaters, so it can be difficult to introduce common allergens early and consistently using a DIY approach. Fortunately, there’s an easier way to introduce allergens in baby’s first year, and follow the USDA and AAAAI guidelines.

Ready. Set. Food! is an allergist-developed, bottle-friendly system for consistently introducing allergens to babies. Our daily system gently and safely introduces allergens in pre-measured amounts, to give babies the best chance at food freedom.

Our Stage 1 and Stage 2 Mix-Ins let you start introducing peanut, egg and milk as early as 4-6 months of age, in line with medical guidelines. And since they safely mix with a bottle of breastmilk or formula, you can start introducing allergens to any baby as early as 4 months (even if they haven’t yet started solids.)

Once baby is regularly eating solid foods, they can start Stage 3, which continually introduces babies to 9 top allergens. Stage 3 Mix-Ins mix with food and introduce wheat, soy, sesame, and three types of tree nuts (almond, cashew, and walnut), along with peanut, egg and milk.

We also offer Organic Baby Oatmeal, with the same 9 top allergens already mixed in, as a convenient option for babies who are consistently eating solids.

All four options are 100% organic and contain no added sugar.

With Ready. Set. Food!, early allergen introduction has never been easier! Give your baby a head start towards a healthier future today.

Introduce Allergens Safely and Easily with Ready. Set. Food!

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.