The short answer: Start offering common allergens like peanuts and eggs around 6 months, but not before 4 months, once your baby can handle solids. Early, regular introduction substantially lowers the risk of allergies (especially to peanut and egg), and delaying these foods beyond this window can increase that risk in some babies.
I know this feels counterintuitive. For years, parents were told to wait. But three major studies changed everything, and as a parent who navigated this with my own kids, I can tell you the current guidelines are both evidence-backed and surprisingly straightforward once you understand them.
Why Food Allergies Matter More Than Ever
About 1 in 13 children now has a diagnosed food allergy – a rate that appears to have increased over recent decades. Milk, egg, and peanut are among the most common triggers in infancy, accounting for many early allergic reactions.
The stakes range from mild discomfort to life-threatening anaphylaxis, making the "when and how" of first foods genuinely nerve-wracking for families.
The Research That Changed Everything
The LEAP Study (2015): Peanuts
Researchers tracked 640 high-risk infants (those with severe eczema or existing egg allergy) from 4–11 months through age 5. Half ate peanut-containing foods multiple times weekly; half avoided peanuts completely.
The result: Only 3% of early consumers developed peanut allergy versus 17% of avoiders – an 81% reduction in risk.
This single trial flipped decades of medical advice on its head.
The EAT Study (2016): Multiple Allergens
British researchers asked whether introducing six common allergens (peanuts, egg, milk, wheat, sesame, fish) around 3 months—alongside continued breastfeeding—could prevent allergies.
The finding: Families who maintained early introduction showed significantly lower peanut and egg allergy rates, with no negative impact on breastfeeding. Consistency mattered: regular, sustained exposure built tolerance.
The PETIT Study (2017): Eggs for High-Risk Babies
Japanese scientists gave infants with eczema gradually increasing amounts of heated egg powder starting around 6 months.
The outcome: The trial stopped early because results were so clear – early egg introduction safely and effectively prevented egg allergy in vulnerable babies.
What Leading Medical Groups Now Recommend
The American Academy of Pediatrics (AAP), National Institutes of Health (NIH), and American Academy of Allergy, Asthma & Immunology (AAAAI) all now support early introduction of allergenic foods, especially peanut and egg, as a way to help prevent food allergies, particularly in high‑risk infants.
For babies with eczema or existing food allergies: Consult your pediatrician or allergist before starting. They may recommend timing, supervised introduction, or allergy testing first.
For most infants: Introducing common allergens around 6 months, but not before 4 months, when your baby is developmentally ready for solids is safe and beneficial when approached thoughtfully.
How to Actually Do This (The Practical Part)
Before You Start
- Make sure your baby is healthy so you can spot any changes
- Have an adult present for at least 2 hours after each new food
- Introduce one allergen at a time, waiting 3–5 days before adding another
Watch For These Reactions
- Hives or skin rash
- Vomiting or diarrhea
- Swelling (especially face, lips, tongue)
- Difficulty breathing or persistent coughing
Call 911 immediately if: Your child has trouble breathing, becomes limp or pale, or shows multiple symptoms simultaneously (like hives plus vomiting).
For milder symptoms, contact your pediatrician – some reactions appear gradually.
Safe Preparation Methods
Peanuts:
Mix 2 teaspoons smooth peanut butter with warm water or breastmilk until thin and smooth. Offer a small amount on a spoon. Peanut puffs (like Bamba, used in the LEAP study) work well for slightly older babies who can handle dissolvable snacks. Never offer whole nuts or thick peanut butter – they are major choking hazards.
Eggs:
Hard-boiled or scrambled eggs mashed with breastmilk, formula, or water create the right soft, pureed texture. Introduce egg alone first, without dairy or other new ingredients mixed in.
Dairy:
Plain yogurt makes an easy starter, followed by small cheese portions. Keep breastmilk or formula as the primary milk source until 12 months (avoid using regular cow’s milk).
The Key to Success: Consistency
Once you've introduced an allergen without reaction, keep offering it several times a week. The immune system needs regular exposure to maintain tolerance—a one-time introduction won't do it.
Think of it like learning a language: occasional practice builds fluency, but sporadic exposure leads to forgetting.
What I Wish I'd Known Earlier
When introducing allergens with my second child, I was still anxious despite knowing the research. Here's what actually helped:
- Starting mid-morning gave me the full day to watch for reactions
- Keeping a simple food diary (just dates and what I offered) helped me track patterns
- Choosing calm, unhurried days for new introductions reduced my stress
- Having an action plan written down (pediatrician's number, nearest ER) meant I didn't panic when my baby developed mild eczema patches after eggs (turned out to be unrelated)
Important Context
These landmark studies were conducted under medical supervision with specific protocols. While the principles apply broadly, every baby is different – particularly those with existing allergies or severe eczema.
Your pediatrician or allergist should always be part of your allergen introduction plan. They know your child's complete health picture and can provide personalized guidance.
The Bottom Line
The science is remarkably clear: introducing allergenic foods early (4–6 months) and consistently offers genuine protection against food allergies. Waiting doesn't help babies' immune systems "mature" – it increases allergy risk.
Yes, it feels strange when you remember old advice. But sometimes science advances and we change course based on better evidence. This is one of those times.
Our next recos: The New Baby Food Guidelines
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