For decades, parents were told to wait until their child was two or three years old before giving them peanut butter. It seemed like a safe move - after all, peanuts can cause life-threatening reactions. But by 2015, something strange had happened: peanut allergies in kids had more than quadrupled since the 1990s. Something was wrong with the advice. Then came the LEAP study, a landmark trial that flipped everything we thought we knew about peanut allergies on its head.
Why Early Introduction Works
The LEAP study, published in 2015, followed over 600 babies at high risk for peanut allergy - those with severe eczema or egg allergy. Half were told to avoid peanuts entirely until age five. The other half started eating peanut products as early as four months old, about 2 grams of peanut protein three times a week. By age five, the group that ate peanuts early had an 86% lower rate of peanut allergy. That’s not a small drop. That’s a game-changer. The reason this works isn’t magic. It’s biology. Babies’ immune systems are still learning what’s dangerous and what’s not. When you expose them to peanut protein early - in a safe, controlled way - their bodies learn to recognize it as harmless, not as a threat. Delaying exposure gives the immune system more time to misread peanut as an invader. Once that happens, it’s hard to undo.Who Should Start Early - and When
Not all babies need the same approach. The NIAID guidelines, updated in 2017 and still current today, break it down into three risk levels:- High-risk infants - those with severe eczema or egg allergy - should be evaluated by a doctor between 4 and 6 months. If allergy testing shows no reaction, they can start eating peanut protein at home or under medical supervision. The goal is 2 grams of peanut protein, three times a week.
- Moderate-risk infants - those with mild to moderate eczema - can start peanut around 6 months, usually at home, without testing.
- Low-risk infants - no eczema or food allergies - can have peanut introduced anytime after starting solids, around 6 months, just like any other food.
How to Safely Introduce Peanut
You don’t give a 4-month-old a spoonful of peanut butter. That’s a choking hazard. Instead, you make it safe:- Use smooth peanut butter - no chunks, no crunchy.
- Thicken it: Mix 2 teaspoons of peanut butter with 2-3 tablespoons of warm water, breast milk, or formula until it’s a thin, runny paste.
- Or mix it into infant cereal, pureed fruits, or vegetables.
- Another option: Use Bamba, a puffed corn snack made with peanut, which is soft and dissolves easily.
What About Oral Immunotherapy (OIT)?
OIT is not prevention. It’s treatment. If your child already has a peanut allergy, OIT is a process where they’re given tiny, gradually increasing doses of peanut protein under medical supervision to build tolerance. It doesn’t cure the allergy - it helps them handle accidental exposures without a severe reaction. The FDA approved Palforzia in 2020, a powdered peanut protein used for OIT in kids ages 4-17. But OIT has big downsides: daily dosing, risk of reactions (even mild ones like stomach upset or hives), and it only works as long as you keep taking it. Stop the doses, and the allergy often comes back. That’s why prevention through early introduction is so powerful. It doesn’t require daily pills. It doesn’t need ongoing medical oversight after the first few weeks. It’s a one-time window of opportunity - and once you pass it, you can’t get it back.Why So Many Parents Still Wait
Despite clear guidelines, only about 39% of high-risk infants in the U.S. are getting peanut introduced early. Why?- Parents are scared. A 2022 survey found that 62% of parents worried about causing a reaction.
- Doctors aren’t always on the same page. One study showed only 54% of pediatricians knew the correct NIAID guidelines.
- Confusion about what’s safe. Some parents think they need to wait until the child is older because they heard “peanuts are dangerous.” They don’t realize it’s about form, not timing.
- Disparities persist. Black and Hispanic infants are 22% less likely to get early peanut exposure than white infants, contributing to higher allergy rates in these communities.
What Happens After Introduction?
Once you start, you don’t stop. The research shows that regular exposure - at least three times a week - is key. You can’t just give peanut once and call it done. The immune system needs consistent reinforcement. And here’s the best part: the protection lasts. The LEAP follow-up study showed that even after a full year of avoiding peanut, kids who had eaten it early still had low allergy rates. That’s not just desensitization - it’s true tolerance. Their bodies learned peanut wasn’t a threat, and they never forgot.
What Doesn’t Work
You might hear that eating peanuts while pregnant or breastfeeding prevents allergies. Or that giving your baby probiotics or vitamin D helps. But the science doesn’t back it up. Cochrane reviews have looked at dozens of studies - and none of these approaches show any real effect on peanut allergy prevention. The only proven method? Early and regular exposure to peanut protein in infancy.The Bigger Picture
Since the 2017 guidelines, peanut allergy rates in U.S. children have dropped from 2.2% to 1.6%. That’s about 300,000 fewer kids with a lifelong, potentially deadly allergy. If we get early introduction up to 65% of high-risk infants - instead of the current 39% - experts predict peanut allergy rates could fall to 1.2% by 2030. This isn’t just about peanuts. The same approach is now being tested with eggs, milk, and other common allergens. The idea? If you can teach the immune system early, you might prevent multiple allergies at once.What to Do Now
If you’re expecting or have a baby under 12 months:- If your child has severe eczema or egg allergy - talk to your pediatrician before 6 months. Ask about allergy testing and safe peanut introduction.
- If your child has mild to moderate eczema - start peanut around 6 months at home. Use smooth peanut butter mixed with water or formula.
- If your child has no eczema or food allergies - introduce peanut when you start solids, around 6 months. No testing needed.
Can I give my baby whole peanuts or peanut butter straight from the jar?
No. Whole peanuts are a choking hazard and should never be given to children under 5. Even thick, sticky peanut butter can be dangerous for infants. Always thin it with water, breast milk, or formula, or use a soft, dissolvable peanut product like Bamba.
Is it too late to start if my child is already 1 year old?
It’s not ideal, but it’s not too late. The strongest protection happens before 6 months, but introducing peanut between 1 and 5 years can still reduce risk - especially if your child is at high risk. Talk to your pediatrician or allergist first. Testing may be needed.
Do I need to test my baby for peanut allergy before introducing it?
Only if your baby is high-risk - meaning they have severe eczema or an egg allergy. In that case, see a doctor first. They may recommend a skin prick test or blood test. If the test is negative, you can start at home. For mild eczema or no eczema, testing isn’t needed.
Can I use peanut oil instead of peanut butter?
No. Peanut oil, especially refined peanut oil, doesn’t contain the proteins that trigger allergies. To prevent allergy, you need actual peanut protein - not just flavor or scent. Use smooth peanut butter, peanut flour, or peanut-containing infant snacks like Bamba.
What if my baby has a reaction the first time?
Mild reactions like a rash or lip swelling are possible but rare. If your baby develops hives, vomiting, difficulty breathing, or swelling of the face or tongue, call 911 immediately. If it’s a mild reaction, stop giving peanut and contact your pediatrician. They may refer you to an allergist. Don’t panic - most babies tolerate peanut without issue, especially when introduced properly.
