Can Early Introduction Help Prevent Food Allergies in Infants?

How we’ve rethought starting solids and allergen advice

When it comes to introducing foods to infants, the guidance parents receive can feel like a moving target. Not long ago, pediatricians recommended delaying the introduction of potentially allergenic foods like peanuts, eggs, and shellfish. Today, we encourage parents to introduce these foods earlier. 

So, what changed? Let’s explore the evolving science behind early introductions to allergens and how it might help prevent them in your little one.

Outdated advice on infant food allergies: What we used to get wrong

What earlier guidelines said about foods like peanuts, eggs, and dairy

For decades, the go-to advice was to delay introducing allergenic foods in babies. In the 1990s and early 2000s, the American Academy of Pediatrics (AAP) recommended waiting until age 1 for cow’s milk, age 2 for eggs, and age 3 for peanuts, tree nuts, fish, and shellfish. (This was before sesame made the top allergen list.)

There was also a time when breastfeeding parents were encouraged to cut out allergens from their own diets, in hopes it would help prevent allergies.

This made sense at the time, it was thought that waiting would give a baby’s immune system time to develop. But despite the caution, food allergies kept rising, especially in places like the U.S. That’s why these guidelines were pulled back in 2008, and more research was performed. 

The LEAP study: What changed everything about food allergy prevention

How early peanut introduction helped babies at higher risk

A game-changer came in 2015 with the LEAP (Learning Early About Peanut Allergy) study. Researchers conducted a groundbreaking trial involving hundreds of infants at high risk for peanut allergy (because of severe eczema or egg allergy).

Researchers divided babies into two groups:

• One group avoided peanuts until age 5

• The other group started eating peanut-containing foods regularly between 4–11 months

The result? The early-introduction group had significantly fewer peanut allergies by age 5. Especially for those already considered higher risk.

This study overturned decades of assumptions!! It suggested that early introduction of allergenic foods in infants could actually help prevent allergies. Turns out, earlier might be the new safer!

What the latest guidelines say about introducing allergens

When and how experts now recommend starting allergenic foods

After the LEAP study, guidelines from the AAP and the National Institute of Allergy and Infectious Diseases (NIAID) were updated.

Here’s what they now suggest:

• For most babies: introduce allergenic foods around 4–6 months

• For high-risk babies (with eczema or egg allergy): introduce peanut-containing foods as early as 4 months

The key idea? Early and ongoing exposure may help your baby’s immune system get comfortable with these foods—kind of like saying, “Hey, we know this one, it’s okay.”

So if you think your baby’s ready to start building that comfort, we’ve got you covered. Check out our 6 tips for safely introducing the top 9 allergens to begin gently and confidently.

Why early exposure might help prevent infant food allergies

The exact mechanisms are still being studied, but allergists and research scientists believe that:

• Oral exposure to an allergen during infancy helps the immune system develop tolerance.
  

• Delayed exposure leaves the immune system unfamiliar with the food proteins, increasing the risk of an allergic reaction later.
  

• Skin exposure to allergens (through eczema or environmental contact) without oral exposure may increase allergy risk.
  

This is sometimes called the "dual-allergen exposure hypothesis", highlighting the importance of early oral exposure compared to accidental skin exposure.

How to introduce allergenic foods gently and safely

1. Talk with your pediatrician, especially if there’s eczema or family history

If your baby has severe eczema, a known food allergy, or food allergies run in your family, check in with your pediatrician. Some families find allergy testing helpful before starting certain foods.

2. Take it one food at a time, at your baby’s pace

Start simple. Try one new food at a time and wait about three days before adding another. This helps you spot any reactions without overwhelm. 

3. Safe ways to serve common allergens to babies

For the Bébé Foodie App, I created an allergen timeline and guides to help make this easier, but here’s a quick cheat sheet:

Peanuts

Skip the whole peanuts (they’re a choking hazard). Try:

•  Thinned peanut butter mixed with breastmilk, formula, or water
  
  
• Peanut powder stirred into oatmeal or yogurt
  
  
• Baby-safe peanut snacks

Eggs

Go for well-cooked forms:

• Scrambled, hard-boiled, or baked

• Pasteurized powdered eggs can be used too

• Eggs can be given baked into pancakes for an easy BLW food

Dairy

Offer small, baby-friendly amounts of:

• Yogurt

• Cheese

• Cow’s milk-based formula (not straight-up milk yet!)

Know what reactions to watch for (and when to call for help)

Allergic reactions in babies can look like:

• Hives or rash

• Vomiting

• Coughing or wheezing

• Swelling around lips or face

Severe reactions (called anaphylaxis) are rare—but they need immediate medical care.

Keep offering foods regularly to build tolerance over time

Once a food is introduced, regular exposure (several times a week) seems important for maintaining tolerance.

Real parent questions about infant food allergies

What if my baby has mild eczema?

Babies with mild eczema are considered at moderate risk for food allergies. Early introduction is still recommended, but you should speak to your pediatrician or pediatric allergist to discuss risks and benefits of food allergy testing. 

Can I introduce foods like shellfish or tree nuts too?

Most research focuses on peanuts and eggs, but early introduction may help with other allergens too. The same gentle, go-slow approach works well here. But the short answer is if you are not ready right when your baby starts solids, no need to dive into lobster bisque just yet. To make it easier, our app’s allergen timeline is designed to help you introduce all the top allergens before your baby turns 1—at your own pace, with confidence.

Is early introduction still helpful if my baby’s low risk?

For babies without eczema or food allergies, early introduction is still beneficial and safe. The goal is to introduce a diverse diet starting around 6 months, while continuing breastfeeding if possible. Diet diversity helps build and maintain a healthy gut microbiome, which likely plays an important role in food tolerance. 

Should I avoid allergens while pregnant or breastfeeding?

No need to cut them out. Research shows that avoiding allergens during pregnancy or breastfeeding doesn’t reduce allergy risk, so enjoy your food and feed with confidence.

The bottom line: Feed with confidence, not fear

Our understanding of early allergen introduction has evolved. What once seemed like common sense - "wait to introduce risky foods" - turned out to be the wrong approach. Thanks to high-quality research like the LEAP study and others, parents today can feel empowered to offer a variety of foods early and often, giving babies a better shot at a future free from food allergies.

Of course, every child is different. Always work with your pediatrician, and trust your instincts. Introducing new foods can be an exciting adventure for your baby, and we are here at BebeFoodie to support you on this journey.

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References

1. Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, Brough HA, Phippard D, Basting M, Feeney M, Turcanu V, Sever ML, Gomez Lorenzo M, Plaut M, Lack G; LEAP Study Team. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015 Feb 26;372(9):803-13. 

2. Fleischer DM, Chan ES, Venter C, Spergel JM, Abrams EM, Stukus D, Groetch M, Shaker M, Greenhawt M. 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. J Allergy Clin Immunol Pract. 2021 Jan;9(1):22-43.e4.

Written by Dr. Taylor Lin

Pediatric Allergist & Advisor at Bébé Foodie

Meet Dr. Taylor Lin, our go-to expert on allergies and immunology! Dr. Lin serves families in southeast Michigan as an allergy and immunology physician with Allergy & Immunology Associates. With top-notch training from the University of Michigan and a specialty fellowship in pediatric food allergy, she’s not just highly qualified—she’s also a mom to a child with food allergies herself! Dr. Lin directs her clinic's food oral immunotherapy program and brings evidence-based, accessible advice to families through her role with Bébé Foodie.

This blog post is for information purposes only and shouldn’t be used as personal, health, nutritional, or medical advice. Always consult with your pediatrician before making any decisions about your child's health or readiness for various foods.