Preventing Food Allergies: "Feed Early, Feed Often!"

Mar 26
5 min read

📢 Over the past decade, there have been major breakthroughs in food allergy prevention and treatment.

What used to be considered “safe” advice—delaying the introduction of foods like peanuts and eggs—has now been replaced with strong evidence showing the opposite:

Introducing allergenic foods early can actually help prevent allergies.

We now have a large body of high-quality research (summarized below in plain english) showing that early and regular introduction of common allergenic foods (cow's milk, egg, peanut, tree nuts, sesame, wheat, soy, fish) can significantly reduce the risk of developing food allergies.

This research has formed the basis of recommendations from the Canadian Society of Allergy and Clinical Immunology, the Canadian Pediatric Society (CPS), and the American Academy of Pediatrics: allergenic foods should be fed early, once they are developmentally ready for solid foods (4-6 months old).

Not every child will be prevented from developing a food allergy—there are still genetic and environmental factors we don’t fully understand. But for most children,

Early and ongoing exposure lowers risk.

Once your baby has eaten the food, and if there is no allergic reaction, it’s very important to keep feeding that food to your baby at least once a week to help prevent the development of a food allergy.

Frequently Asked Questions

Q: Should I test my baby before introducing allergenic foods?

No. Both the Canadian Pediatric Society and the American Academy of Pediatrics recommend against routine pre-testing, even for high-risk infants (those with egg allergy, severe eczema, or both).

Q: Is it safe to introduce these foods at home?

Yes.

Introduce new foods at home, not at daycare
You do not need to go to an ER or your doctor's office to try foods for the first time
Make sure your baby is well and will be awake for at least 2 hours after ingestion
An adult should observe your child for 2 hours after ingestion

Q: Should I test the food on my baby’s skin first?

No.

This can cause irritation and does not predict whether your baby is allergic. The only meaningful test is eating the food.

Q: What if my baby is older than 6 months?

That’s okay! It’s not too late—you can still introduce allergenic foods safely in age-appropriate forms.

Q: How do I introduce peanut?

Offer a small amount of smooth peanut butter on the tip of a spoon, or mix 1:1 with warm water
You can also use softened peanut puffs (e.g., Bamba).
Never give whole peanuts (choking hazard)
Wait 10 minutes, then continue if no reaction
Continue feeding at least once a week to maintain tolerance

Q: How do I introduce egg?

Use fully cooked egg (boiled, scrambled, or baked)
Both the egg white and egg yolk can be served
Mash or puree and mix with familiar foods
Offer a small amount, wait 10 minutes, then continue if no reaction
Continue feeding at least once a week to maintain tolerance

Q: What if allergies run in the family?

Even if a parent or sibling has a food allergy, early introduction at home is still recommended. If you’re still anxious, talk to your doctor.

Q: How likely is a serious reaction?

The risk is very low, especially for severe reactions.

In the LEAP study (see below), only 2% of high-risk infants reacted the first time they ate peanut, and all had mild reactions limited to the skin.
A 2018 study from Chicago suggested that only 2% of infants experiencing anaphylactic reactions had truly severe symptoms.
Taken together, this suggests that severe reactions in high-risk infants upon first exposure is less than 0.04% (2% of 2%).

The risk of a mild reaction (such as hives) is possibly higher, but less studied.

Q: How do I know if my baby is allergic to a food?

Symptoms usually appear within minutes, but can occur up to 2 hours after ingestion.

Mild symptoms include:

Hives
Rash around the mouth

More serious symptoms include (see my post on anaphylaxis in babies and young children):

Swelling (face, lips, eyes)
Vomiting
Breathing problems (cough, wheeze)
Lethargy or color change

🚨 If severe symptoms occur, call 911 immediately and use EpiPen Jr® if available.

Q: If my baby develops an allergy, will they always be allergic?

Not necessarily! There are exciting new therapies that show a lot of promise including oral immunotherapy (OIT). Any suspected food allergy should be evaluated by a paediatric allergist right away so you can discuss what treatment options are available for your child.

The key studies (in plain language)

1) The LEAP study (Learning Early About Peanut Allergy)

Studied 640 high-risk infants (eczema and/or egg allergy)
Compared early peanut feeding vs avoidance

Result:👉 About an 80% reduction in peanut allergy in the early-introduction group

It also showed that early peanut introduction was safe, even in high-risk babies.

2) The LEAP-On study

This follow-up study asked: Does the benefit last?

Result:👉 Yes—early peanut introduction led to lasting protection, even after a year of stopping peanuts.

3) The PETIT study (Prevention of Egg Allergy with Tiny Amount Intake)

Studied high-risk infants with eczema
Introduced small, gradually increasing amounts of cooked egg

Result:👉 About an 80% reduction in egg allergy

4) Real-world data

A large U.S. study of over 38,000 children under age 3 found that after the implementation of early introduction guidelines in 2017:

Peanut allergy decreased by ~27–43% after the implementation of
Overall food allergies decreased by ~36–38%

A 2024 Canadian study also found that after early peanut introduction guidelines were implemented in 2017, there was a significant decrease in new cases of peanut-related anaphylaxis in children under 2 years old.

What's The Bottom Line?

Introduce allergenic foods around 6 months (not before 4 months)
Early introduction reduces allergy risk
This is especially important for babies with eczema
Once introduced, keep feeding these foods regularly (about once a week)
Make sure your baby is developmentally ready for solids (check out this resource if you're unsure)

References

American Academy of Pediatrics. Guidelines for Early Food Introduction and Prevention of Food Allergy. Pediatrics. 2025. https://publications.aap.org/pediatrics/article/156/5/e2024070516/204636
Du Toit G, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy (LEAP). New England Journal of Medicine. 2015;372:803–813.
Du Toit G, Sayre PH, Roberts G, et al. Effect of avoidance on peanut allergy after early peanut consumption (LEAP-On). New England Journal of Medicine. 2016;374(15):1435–1443.
Natsume O, Kabashima S, Nakazato J, et al. Two-step egg introduction for prevention of egg allergy in high-risk infants (PETIT trial). Lancet. 2017;389(10066):276–286.
Yu J, Lanoue D, Mir A, et al. Trends of peanut-induced anaphylaxis rates before and after early peanut introduction guidelines in Montreal, Canada. Journal of Allergy and Clinical Immunology: In Practice. 2024;12(9):2439–2444.e4.
Canadian Paediatric Society – Caring for Kids. Introducing solid foods to your baby. https://caringforkids.cps.ca/handouts/pregnancy-and-babies/feeding_your_baby_in_the_first_year
Canadian Paediatric Society. Position statement: Introduction of allergenic solids. https://cps.ca/en/documents/position/allergenic-solids
Food Allergy Canada. Early Food Introduction Guide. https://foodallergycanada.ca/wp-content/uploads/EarlyIntro_Web.pdf
American Academy of Pediatrics. Updates in Food Allergy Prevention in Children. Pediatrics. 2023;152(5):e2023062836. https://publications.aap.org/pediatrics/article/152/5/e2023062836/194356