At what age should I introduce allergy-causing foods?

Learn why you should start introducing common allergy-causing foods (peanut, egg, and milk) before your baby turns one year old. Also, learn how late is too late to start feeding your baby these foods for allergy prevention.

In this article, you’ll learn about the benefits of introducing allergens at 4-11 months, including:

  • The LEAP study shows that peanut introduction helps prevent developing peanut allergies in over 80% of infants
  • Avoids putting your baby at an increased risk for developing food allergies which is associated with delaying allergen introduction, as also shown by the LEAP study on peanut allergy
  • Follows recommendations from leading medical organizations (e.g. AAP, NIH and NIAID)
  • Maximizes safety as new research shows introducing allergens in the first year of life is the safest time

All babies are at risk for food allergies. Babies aren’t born with these allergies, but instead develop them over time. And since every baby is different, food allergies can develop at any time.

Introducing common allergy-causing foods (peanut, egg, and milk) early and often can help prevent food allergies before they start.

The best time to introduce these foods for prevention is before your baby turns one---the earlier the better. The longer you wait, the more likely your baby has already started developing a food allergy.

It’s recommended to start feeding your baby these foods as early as 4-6 months of age. Here’s why.

Landmark studies: Starting between 4-6 months is best

Recent landmark studies (LEAP, EAT, PETIT) show:

Introducing infants to common allergy-causing foods early and often can help reduce their food allergy risk by up to 80%.

  • Introduce peanut, egg, and milk to your baby as early as 4-6 months of age, for the best chance of preventing allergies to these foods.
  • Around this time, babies enter a critical window where eating these foods helps their immune system build up tolerance.
  • If babies don’t eat these foods during this window, they’re much more likely to develop allergies to these foods.
  • This is why it is so important to start feeding baby peanut, egg, and milk between 4-6 months of age.
  • But introducing these foods only once or twice isn’t enough to build up your baby’s tolerance.
  • For the best chance of preventing food allergies, introduce these foods 2-7 times per week for at least several months.

New clinical guidelines are based on these studies

Based on these studies’ results, new clinical guidelines support feeding your baby allergy-causing foods starting as early as 4-6 months of age, to help prevent food allergies.

This includes guidelines from the:

According to all of these organizations:

  • Introducing common allergens (like peanut and egg) as early as 4-6 months is particularly crucial for babies at high risk of food allergies.
  • Regardless of your baby’s risk for a food allergy, you should introduce allergens before your baby turns one year old.

The CHILD cohort study underlines the importance of starting early

A JACI study based on data from Canada’s CHILD cohort further supports early introduction, regardless of your baby’s risk of food allergies. The longer you wait, the greater your baby’s risk of developing a food allergy.

  • Babies who didn’t eat peanut during their first year of life were over four times more likely to develop a peanut allergy by age three, compared to babies who started eating peanut within their first year of life.
  • Children who didn’t eat peanut before 18 months were over seven times more likely to develop peanut allergies or sensitization, compared to children who started eating peanut in their first 9 months of life. (Sensitization to peanut increases a baby’s chances of developing a peanut allergy.)
  • None of the babies who ate peanut by six months of age developed sensitization to peanut by age three.
  • Notably, most of the babies in the CHILD cohort were at low risk of developing a peanut allergy.

Before one year of age is also the safest time to introduce allergens

New research from Dr. Jonathan Spergel (Head of Allergy at Children’s Hospital of Philadelphia) and others shows that introducing allergy-causing foods before your baby turns one is safest, compared to introducing these foods later in life.

  • Severe allergic reactions are the least common in infants under age 1.
  • No food allergy deaths were ever reported in infants under age 1.
  • Allergic reactions get more severe as your baby gets older. So, starting as early as possible is the safest way to feed allergens to your baby.

What if my baby is over one year of age?

Dr. Elinor Simons, the CHILD study's lead researcher, recommends that children be introduced to peanut within their first year of life, to lower their risk of developing a food allergy. "If peanut is not introduced before 12 months, it should still be introduced as soon as possible,” emphasizes Dr. Simons.

About the author: Jessica Huhn is a content writer for 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.