When should babies first eat peanut and egg?

For years parents were told to delay peanut and egg. There is now no evidence that delaying allergenic foods past 4 to 6 months prevents allergy, and early peanut introduction may prevent peanut allergy⁸.

Peanut. In the LEAP trial, 640 infants with severe eczema or egg allergy ate or avoided peanut until age 5. Among those with a negative skin-prick test, peanut allergy at 5 years was 13.7% with avoidance and 1.9% with regular peanut⁴. The protection lasted: at age 12, peanut allergy was 15.4% in the original avoidance group and 4.4% in the consumption group⁹.

Egg. Well-cooked egg started at 4 to 6 months probably reduces egg allergy; pasteurized raw egg did not⁷. In Japan, heated egg powder plus careful eczema treatment cut egg allergy in infants with eczema from 38% to 8%¹⁰.

Timing by risk. US guidelines say infants with severe eczema, egg allergy or both can have peanut as early as 4 to 6 months once other solids are going well, with testing strongly considered first. Infants with mild or moderate eczema start around 6 months, and infants with neither can start freely². A North American consensus says to introduce peanut and egg around 6 months but not before 4, and that screening is optional¹.

How much. Guidelines suggest 6 to 7 g of peanut protein weekly over three or more feedings; a first dose is about 2 g, or 2 teaspoons of thinned smooth peanut butter². In the EAT trial, about 2 g a week of peanut or egg-white protein went with lower allergy¹¹.

Textures and choking. Choking is a leading cause of injury and death in children aged 3 and under, and food is a main cause³. Thin peanut butter with water or mix it into puree, and keep egg well cooked. Whole nuts are off the menu under 5, and spoonfuls or lumps of peanut butter under 4².

What does not help. The consensus advises against mothers avoiding allergenic foods in pregnancy or breastfeeding, and found no protective benefit from hydrolyzed formula¹. After the US guidelines, peanut allergy diagnoses in one primary-care network fell from 0.79% to 0.53%¹². For adult nutrition, see eggs and peanuts.

LEAP: the landmark peanut trial

LEAP randomized 640 infants aged 4 to 11 months with severe eczema, egg allergy or both to eat or avoid peanut until 60 months, with separate groups by skin-prick result⁴. Among 530 infants with a negative test, peanut allergy at 60 months was 13.7% with avoidance and 1.9% with consumption (P < 0.001). Among 98 with a 1 to 4 mm wheal, it was 35.3% versus 10.6% (P = 0.004). Serious adverse events did not differ. The 2024 follow-up reached 508 participants (79.4%) at age 12: peanut allergy was 15.4% (38 of 246) in the original avoidance group and 4.4% (11 of 251) in the consumption group, even though both groups had avoided peanut for long periods after age 6⁹. Limits: one trial, a high-risk population, and a high-prevalence setting.

EAT: a broader test that was less clear

EAT randomized 1,303 exclusively breast-fed 3-month-olds from the general population to early introduction of six allergenic foods or exclusive breastfeeding to about 6 months. In the intention-to-treat analysis, food allergy to any of the six foods was 5.6% versus 7.1% (P = 0.32). In the per-protocol analysis, it was 2.4% versus 7.3% (P = 0.01), including peanut (0% versus 2.5%) and egg (1.4% versus 5.5%), with no effects for milk, sesame, fish or wheat. Eating about 2 g a week of peanut or egg-white protein tracked with less allergy, and early introduction of all six foods was hard to sustain but safe¹¹. Per-protocol results are vulnerable to bias, since families who manage the regimen differ from those who do not.

Egg: results depend on the preparation

PETIT randomized 147 infants aged 4 to 5 months with eczema to heated egg powder (50 mg a day from 6 to 9 months, then 250 mg) or placebo, with aggressive eczema treatment. Egg allergy at 12 months was 8% versus 38% (risk ratio 0.221, 95% CI 0.090 to 0.543), though hospital admissions were more common with egg (10% versus none)¹⁰. STEP gave 820 infants with a hereditary risk but no eczema pasteurized raw egg powder from 4 to 6 months; egg allergy was 7.0% versus 10.3% (adjusted RR 0.75, 95% CI 0.48 to 1.17), and 6.1% versus 1.5% stopped because of a confirmed reaction⁵. HEAP gave 383 non-sensitized infants egg-white powder three times a week; sensitization was 5.6% versus 2.6% and allergy 2.1% versus 0.6%, both non-significant, and 16 of the 17 infants already sensitized who were challenged were allergic⁶. A systematic review of 46 studies concluded that well-cooked egg, not pasteurized raw egg, from 4 to 6 months probably reduces egg allergy, and that early regular peanut in at-risk infants probably gives a large reduction in high-prevalence countries. The peanut conclusion rests on moderate-certainty evidence from single trials in high-income countries. Avoiding allergens in pregnancy, vitamins, fish oil, probiotics and emollients may do little, but that evidence is very uncertain⁷.

Guidelines and real-world results

The NIAID-sponsored panel defined three risk groups and recommended about 6 to 7 g of peanut protein weekly, noting whole nuts should not be given before age 5². The 2021 consensus advised peanut and egg around 6 months but not before 4, optional screening, a diverse diet, and no maternal exclusion diets¹. In a before-and-after analysis of a primary-care network, peanut IgE-mediated allergy fell from 0.79% to 0.53% after the 2015 guidance (hazard ratio 0.65, 95% CI 0.55 to 0.77) and to 0.45% after the 2017 addendum (HR 0.55, 95% CI 0.46 to 0.66). That design cannot prove cause¹².

Where the evidence is thin

Peanut and egg are the only foods with solid trial support; milk, sesame, fish and wheat showed no significant effects in EAT. The LEAP follow-up suggests protection can persist without continued regular peanut, but how long regular feeding is needed has not been settled, and most trials were in high-income countries.

Bottom line (confidence 4 of 5)

Early, regular peanut is well supported for high-risk infants and endorsed for others; well-cooked egg is moderately supported. Follow your pediatrician's guidance, especially with eczema or allergy.