— September 17, 2026 · Eating More Eggs and Peanuts in Pregnancy Did Not Lower Infant Food Allergy

Table of Contents

1. At a Glance
2. What Was Done
3. What Was Found, Number by Number
4. How It Was Thought to Work
5. How It Fits With Earlier Research
6. What the Guidelines Already Said
7. What It Cannot Show
8. What the Researchers and Commentators Said
9. What Remains Unknown
10. Sources and Primary Documents
11. Key Research Papers
12. Connections
13. Featured Videos

At a Glance

• Paper — Palmer DJ, Campbell DE, Nanan R, et al. “Trial of a Maternal Diet Rich in Eggs and Peanuts to Reduce Infant Allergy.” New England Journal of Medicine 395(11):1090–1099, issue of September 17, 2026.
• Who — research teams in Perth, Adelaide, Melbourne and Sydney, led by Debra J. Palmer of The Kids Research Institute Australia; funded by Australia’s National Health and Medical Research Council and Australian research and charitable foundations.
• Design — multisite randomised controlled trial (PrEggNut, Australian New Zealand Clinical Trials Registry ACTRN12618000937213). The women knew which diet they followed; the staff who tested the babies did not.
• Size — 2,137 pregnant women: 1,070 assigned to the high egg-and-peanut diet, 1,067 to the standard diet.
• The two diets — at least 6 eggs and 60 peanuts a week, or no more than 3 eggs and 30 peanuts a week, from before 23 weeks of pregnancy until 4 months after birth while breastfeeding.
• Main result — IgE-mediated egg or peanut allergy at 1 year in 7.8% vs 8.4% of babies; relative risk 0.93 (95% CI 0.69 to 1.26); P = 0.65. Not a significant difference.
• Safety — similar in the two groups.

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What Was Done

Who took part. According to the trial protocol, published in BMJ Open in 2022, the women were carrying one baby, were less than 23 weeks pregnant when they joined, and planned to breastfeed for at least 4 months. The baby had to have at least two biological family members (mother, father or siblings) with medically diagnosed allergic disease. News coverage of the paper lists those diseases as asthma, eczema, allergic rhinitis and IgE-mediated food allergy. Women who were themselves allergic to egg or peanut could not join. Recruitment began in October 2018 at sites in Adelaide, Perth, Sydney and Melbourne; published summaries of the paper give the enrolment period as 2018 to 2024.

The two diets. Women were assigned at random, half and half, to one of two diets. The high egg-and-peanut group was asked to eat at least 6 eggs and 60 peanuts every week. The standard group was asked to eat no more than 3 eggs and 30 peanuts a week. Both diets ran from enrolment (before 23 weeks of pregnancy) until the baby was 4 months old, so they covered late pregnancy and the first months of breastfeeding. The protocol links the amounts to the Australian Dietary Guidelines, where one serving of protein foods is “2 large eggs or 30 g nuts.”

What was measured. The main outcome was IgE-mediated egg or peanut allergy in the baby at 1 year. IgE-mediated allergy is the kind driven by IgE antibodies, which produce quick reactions such as hives, swelling, vomiting or anaphylaxis. Under the protocol, a baby with a skin-prick test weal of at least 3 mm then had a medically supervised oral food challenge (lightly cooked scrambled egg, or peanut butter); a documented earlier anaphylactic reaction also counted. Other outcomes included egg and peanut allergy counted separately, sensitisation on skin-prick testing, eczema and its severity, and egg- and peanut-specific antibody levels in some babies.

How big it needed to be. The researchers assumed that 16% of high-risk babies would develop egg or peanut allergy and that the high diet might cut that by 30%, to 11.2%. To detect a change of that size with 85% power, allowing for 10% loss to follow-up, they planned 2,136 women. They enrolled 2,137.

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What Was Found, Number by Number

From the published abstract:

• Main result — 83 of 1,066 babies (7.8%) in the high egg-and-peanut group and 89 of 1,064 (8.4%) in the standard group had IgE-mediated egg or peanut allergy at 1 year. Relative risk 0.93; 95% CI 0.69 to 1.26; P = 0.65.
• Safety — “Safety measures were similar in the two groups.”

From published summaries of the full paper (not checked against the full text by this site):

• Follow-up — seven women were excluded after a miscarriage or stillbirth; the main outcome was directly measured in 1,917 babies (90%), at a median age of 12.9 months.
• Egg allergy alone — 6.2% vs 7.2% (relative risk 0.87; 95% CI 0.62 to 1.21).
• Peanut allergy alone — 2.6% in both groups (relative risk 1.02; 95% CI 0.60 to 1.76).
• Women who kept to the diet and breastfed to 4 months (the per-protocol analysis) — 5.6% vs 6.8% (relative risk 0.80; 95% CI 0.48 to 1.35). Also not a significant difference.
• Eczema — medically diagnosed eczema in 16.4% vs 18.1% at 4 months and 42.8% vs 46.2% at 12 months; neither difference was significant.
• Sensitisation — no significant difference in sensitisation to egg or peanut.
• Keeping to the diet — in the high group, 64.4% met the egg target and 66.6% the peanut target in at least 75% of monthly surveys; in the standard group, 72.7% and 79.7% kept within their limits.
• Serious adverse events (mother or baby) — 3.6% vs 3.8% (P = 0.73). Infant anaphylaxis to egg or peanut — 0.5% vs 0.9% (P = 0.21).

Reading the confidence interval. A relative risk of 0.93 means allergy was 7% less common, in relative terms, in the high-diet group. The 95% confidence interval runs from 0.69 to 1.26: the data fit anything from a 31% lower risk to a 26% higher risk. The trial was designed to detect a 30% reduction (a relative risk of 0.70), and the lower end of the interval just reaches that far. The abstract’s own wording is careful on this point: the high diet “did not result in a significantly lower risk.” The result rules out a large benefit but cannot rule out a modest one, and it equally cannot rule out a modest harm.

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How It Was Thought to Work

The idea behind the trial is called oral tolerance. Normally, when a food protein enters the gut, the immune system learns to treat it as harmless. In food allergy that learning fails, and the body makes IgE antibodies (measured in the blood as immunoglobulin E) against the protein. The paper’s background states that “immune responses leading to food allergy may develop early in life, potentially before the introduction of solid foods,” and that exposure to food allergens in the womb and through breast milk had been proposed as a way to start that learning earlier. The protocol also cites animal studies in which allergen passed through the mother’s milk produced tolerance in the young.

Earlier studies had shown that food proteins from the mother’s diet do reach breast milk:

• Peanut — in a 2001 study, 23 breastfeeding women each ate 50 g of dry-roasted peanuts. Peanut protein appeared in the milk of 11 of them, at a median peak of 200 ng/mL, and both major peanut allergens, Ara h 1 and Ara h 2, were detected.
• Egg — in a 2016 randomised trial from the PrEggNut lead author’s group, each extra egg a mother ate per week was linked to about 25% more ovalbumin (the main egg-white protein) in her milk (95% CI 5% to 48%). One-third of the women had no ovalbumin detected at all. Babies’ egg-specific IgG4 antibody, a marker associated with tolerance, rose by about 22% for each extra egg per week.

PrEggNut tested whether that exposure is enough, at the amounts used, to lower allergy rates. It did not show that it is. The paper’s abstract does not offer an explanation. The small and variable amounts of egg protein reaching milk in the 2016 study are one fact relevant to that question; the trial itself does not test the reason.

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How It Fits With Earlier Research

Observational studies pointed to a benefit. In a 2014 study of 8,205 children of nurses in the United States, children of non-allergic mothers who ate peanuts or tree nuts five or more times a month around pregnancy had lower odds of peanut or tree-nut allergy than children of mothers who ate them less than once a month (odds ratio 0.31; 95% CI 0.13 to 0.75). A second 2014 US study of 1,277 mother–child pairs found that higher peanut intake in the first trimester was linked to lower odds of a peanut allergic reaction in mid-childhood (odds ratio 0.53 for each one-standard-deviation rise in intake; 95% CI 0.30 to 0.94). Studies of this kind show associations. Families who eat more nuts may differ in other ways, and only a randomised trial can separate the diet from those differences. PrEggNut is that trial, and it did not reproduce the association.

Cutting allergens out of the mother’s diet had already been tested. A 2012 Cochrane review of five trials (952 participants) found no protective effect of an allergen-avoidance diet in pregnancy on eczema in the first 18 months, and noted slightly lower weight gain in pregnancy on the restricted diet. A 2018 systematic review in PLoS Medicine, covering 173 studies of maternal and infant dietary exposures other than milk feeding, did not find that maternal avoidance of allergenic foods influenced the risk of allergic or autoimmune disease. The same review found moderate-certainty evidence that fish-oil supplements in pregnancy and breastfeeding were linked to less egg sensitisation (relative risk 0.69); see omega-3 fats in pregnancy. PrEggNut asks the mirror-image question: not whether cutting out egg and peanut helps, but whether eating more of them does.

Feeding the baby directly is where trials had shown an effect. The LEAP trial (2015) randomised 640 infants with severe eczema, egg allergy or both to eat peanut regularly or go without it until age 5. Among the 530 who started with a negative skin-prick test, peanut allergy at 60 months was 13.7% with avoidance and 1.9% with regular peanut. The EAT trial (2016) started six allergenic foods at 3 months in 1,303 breastfed babies from the general population; its main analysis was not significant (food allergy in 7.1% with standard introduction vs 5.6% with early introduction), but among families who kept to the plan it was 7.3% vs 2.4%. The site’s page on peanut allergy and early introduction covers that change in detail. PrEggNut moved the question one step earlier, to the mother’s diet before and soon after birth, and the effect seen with infant feeding did not appear.

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What the Guidelines Already Said

Before this trial, the major allergy guidelines addressed maternal diet in pregnancy and breastfeeding mainly in terms of avoidance:

• American Academy of Pediatrics (2019 clinical report) — “Current evidence does not support a role for maternal dietary restrictions during pregnancy or lactation.”
• European Academy of Allergy and Clinical Immunology (2020 update, published 2021) — the Task Force “suggests against” avoiding dietary food allergens during pregnancy or breastfeeding as a way to prevent food allergy. For infants, it suggests introducing well-cooked egg, and peanut where peanut allergy is common, as part of complementary feeding, and states that the most effective age to introduce egg and peanut appears to be “from four to 6 months of life.”
• American and Canadian allergy societies (2021 joint consensus) — “Maternal exclusion of common allergens during pregnancy and/or lactation as a means to prevent food allergy is not recommended.”
• Australasian Society of Clinical Immunology and Allergy (guideline developed January 2026) — Recommendation 12: “It is not necessary to remove common food allergens from the diet of breastfeeding mothers to prevent food allergy.” The same guideline recommends including well-cooked egg and peanut in an age-appropriate form in the infant’s diet soon after the infant is developmentally ready and has started solid foods.
• US National Institute of Allergy and Infectious Diseases (2017 addendum) — three guidelines, by infant risk level, on early introduction of peanut-containing foods to infants.

The passages quoted above are about not cutting foods out and about feeding infants; none of them proposes eating extra egg or peanut in pregnancy as a prevention measure. PrEggNut tested exactly that idea, and its result is consistent with the guidelines as they stood.

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What It Cannot Show

• Less allergy than expected. The trial was planned around a 16% allergy rate; the rate seen was about 8%. The authors, as quoted in published reports, write that this “may have reduced our ability to detect an effect.” The confidence interval does not exclude the 30% reduction the trial was built to find.
• Imperfect contrast between the diets. About two-thirds of women in the high group met their targets. An independent commentator noted that the standard diet set an upper limit with no lower limit, so a woman who ate no egg or peanut counted as keeping to it, and that the paper does not report how many women ate none.
• Only high-risk families. Every baby had at least two close relatives with allergic disease. The trial says nothing directly about babies at ordinary risk.
• Only age 1, only two foods. The main report covers allergy at 1 year and only egg and peanut. Later childhood allergy and other foods were not part of this result.
• Current infant feeding in both groups. According to the same commentator, both groups received infant-feeding guidance and introduced egg and peanut at a median of 6.5 months. The trial therefore tests the mother’s diet on top of present-day infant feeding, not in its place.
• Open diets. The women could not be blinded to what they ate, although outcome assessors were.
• Australia only. All four sites were in Australian cities.

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What the Researchers and Commentators Said

Debra J. Palmer, associate professor and head of nutrition in early life at The Kids Research Institute Australia and the trial’s lead author, spoke to the medical news service Healio (article dated September 24, 2026). She described the original reasoning: “Our previous research has found that some babies are already prone to developing a food allergy prior to commencing solid foods, so exposures to food allergens in utero and through breast milk were thought to have a potential beneficial effect to initiate early life food allergen immune tolerance and hence could be a strategy to prevent food allergies in children.”

On the result, she said: “We were surprised with the trial findings as we had expected that the mothers eating higher amounts of eggs and peanuts during pregnancy and breastfeeding would have reduced egg and peanut allergies in their babies.” She also said: “Based on these new large-scale trial results, clinicians can reassure pregnant women that they do not need to eat high amounts of common food allergy causing foods (such as eggs and peanuts) to reduce the risk of their baby developing these food allergies.” And on next steps: “We now need to focus our research on investigating other maternal diet and environmental exposures during pregnancy to identify new strategies to prevent child food allergies.”

In the same article, Carina Venter, a dietitian and researcher at the University of Southampton who reported no relevant financial disclosures, called PrEggNut “the first adequately powered randomized trial to test the question in the opposite direction. Not whether avoidance harms, but whether high intake helps.” She cautioned that “this is ‘no detectable effect,’ not ‘no effect.’” She also noted that “125 eligible women declined to take part at all because they did not want to eat that much egg and peanut,” and that “The investigators expected 16% prevalence and found 8% in high-risk infants,” which she attributed to early-introduction guidance working across the population. That last point is her interpretation; the trial was not designed to test it.

The journal’s editorial, by Maria C. Jenmalm, was titled “Maternal Allergen Consumption and Infant Food Allergy — Reassurance, Not Prescription.” Its text was not available to this site.

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What Remains Unknown

• Later childhood. Whether the two groups differ in allergy, eczema or asthma after age 1 is not reported in this paper.
• Breastfeeding alone, and other nuts. Several PrEggNut investigators have published the protocol for a separate trial, Nuts For Babies (BMJ Open, October 2025). It tests a high peanut and cashew diet only during the first 6 months of breastfeeding: at least 60 peanuts and 40 cashews a week, compared with no more than 20 peanuts and 12 cashews. The planned size is 4,412 participants, with peanut or cashew allergy measured up to 18 months of age.
• Women who ate none. How babies fared when their mothers ate no egg or peanut at all is not reported; the trial had no avoidance group.
• Why the allergy rate was half the expected rate. Explanations have been offered, but the trial was not built to answer that question.
• Other parts of the mother’s diet and environment. The lead author names these as the next research focus. In the 2018 systematic review, fish oil in pregnancy and breastfeeding was the dietary exposure with moderate-certainty evidence for less egg sensitisation.

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Sources and Primary Documents

Main-result figures come from the PubMed abstract and the Crossref record of the paper; design details come from the open-access protocol and the trial registry. Secondary-outcome, adherence and safety figures come from news summaries of the full paper and are marked as such above.

1. Palmer DJ, Campbell DE, Nanan R, Hsu PS, Jorgensen AM, O’Sullivan M, Netting MJ, McWilliam V, Prescott SL, Gold MS, Perrett KP, Makrides M, Sullivan TR (2026). Trial of a Maternal Diet Rich in Eggs and Peanuts to Reduce Infant Allergy. New England Journal of Medicine 395(11):1090-1099. — doi:10.1056/NEJMoa2605659 · PubMed PMID: 42748429
2. Jenmalm MC (2026). Maternal Allergen Consumption and Infant Food Allergy — Reassurance, Not Prescription. New England Journal of Medicine 395(11):1129-1130 (editorial). — doi:10.1056/NEJMe2610158 · PubMed PMID: 42748436
3. Palmer DJ, Sullivan TR, Campbell DE, Nanan R, Gold MS, Hsu PS, et al. (2022). PrEggNut Study: protocol for a randomised controlled trial investigating the effect of a maternal diet rich in eggs and peanuts from <23 weeks’ gestation during pregnancy to 4 months’ lactation on infant IgE-mediated egg and peanut allergy outcomes. BMJ Open 12(6):e056925. — doi:10.1136/bmjopen-2021-056925 · PubMed PMID: 35697444
4. Australian New Zealand Clinical Trials Registry. Maternal diet rich in eggs and peanuts to reduce food allergies in infants: a randomised controlled trial (PrEggNut Study). — ACTRN12618000937213
5. Australasian Society of Clinical Immunology and Allergy (2026). ASCIA Guideline: Infant Feeding for Food Allergy Prevention (content developed January 2026). — allergy.org.au

News summaries of the full paper: Healio, September 24, 2026 (interview with the lead author and an independent perspective); News-Medical, September 17, 2026 (adherence and safety figures); 2 Minute Medicine (secondary outcomes with confidence intervals).

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Key Research Papers

Background papers for this story: earlier observational studies, avoidance trials, infant-feeding trials, breast-milk studies and guidelines. Each entry was checked against PubMed and, for most, Crossref before it was written down.

1. Frazier AL, Camargo CA Jr, Malspeis S, Willett WC, Young MC (2014). Prospective study of peripregnancy consumption of peanuts or tree nuts by mothers and the risk of peanut or tree nut allergy in their offspring. JAMA Pediatrics 168(2):156-162. — PubMed PMID: 24366539
2. Bunyavanich S, Rifas-Shiman SL, Platts-Mills TA, Workman L, Sordillo JE, Camargo CA Jr, et al. (2014). Peanut, milk, and wheat intake during pregnancy is associated with reduced allergy and asthma in children. Journal of Allergy and Clinical Immunology 133(5):1373-1382. — PubMed PMID: 24522094
3. Kramer MS, Kakuma R (2012). Maternal dietary antigen avoidance during pregnancy or lactation, or both, for preventing or treating atopic disease in the child. Cochrane Database of Systematic Reviews 2012(9):CD000133. — PubMed PMID: 22972039
4. Garcia-Larsen V, Ierodiakonou D, Jarrold K, Cunha S, Chivinge J, Robinson Z, et al. (2018). Diet during pregnancy and infancy and risk of allergic or autoimmune disease: A systematic review and meta-analysis. PLoS Medicine 15(2):e1002507. — PubMed PMID: 29489823
5. Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, et al. (2015). Randomized trial of peanut consumption in infants at risk for peanut allergy. New England Journal of Medicine 372(9):803-813. — PubMed PMID: 25705822
6. Perkin MR, Logan K, Tseng A, Raji B, Ayis S, Peacock J, et al. (2016). Randomized Trial of Introduction of Allergenic Foods in Breast-Fed Infants. New England Journal of Medicine 374(18):1733-1743. — PubMed PMID: 26943128
7. Vadas P, Wai Y, Burks W, Perelman B (2001). Detection of peanut allergens in breast milk of lactating women. JAMA 285(13):1746-1748. — PubMed PMID: 11277829
8. Metcalfe JR, Marsh JA, D’Vaz N, Geddes DT, Lai CT, Prescott SL, Palmer DJ (2016). Effects of maternal dietary egg intake during early lactation on human milk ovalbumin concentration: a randomized controlled trial. Clinical and Experimental Allergy 46(12):1605-1613. — PubMed PMID: 27562481
9. Greer FR, Sicherer SH, Burks AW; Committee on Nutrition; Section on Allergy and Immunology (2019). The Effects of Early Nutritional Interventions on the Development of Atopic Disease in Infants and Children: The Role of Maternal Dietary Restriction, Breastfeeding, Hydrolyzed Formulas, and Timing of Introduction of Allergenic Complementary Foods. Pediatrics 143(4):e20190281. — PubMed PMID: 30886111
10. Halken S, Muraro A, de Silva D, Khaleva E, Angier E, Arasi S, et al. (2021). EAACI guideline: Preventing the development of food allergy in infants and young children (2020 update). Pediatric Allergy and Immunology 32(5):843-858. — PubMed PMID: 33710678
11. Fleischer DM, Chan ES, Venter C, Spergel JM, Abrams EM, Stukus D, et al. (2021). A Consensus Approach to the Primary Prevention of Food Allergy Through Nutrition: Guidance from the American Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; and the Canadian Society for Allergy and Clinical Immunology. Journal of Allergy and Clinical Immunology: In Practice 9(1):22-43.e4. — PubMed PMID: 33250376
12. Togias A, Cooper SF, Acebal ML, Assa’ad A, Baker JR Jr, Beck LA, et al. (2017). Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. Journal of Allergy and Clinical Immunology 139(1):29-44. — PubMed PMID: 28065278
13. Sullivan TR, McWilliam V, O’Sullivan M, Netting M, Perrella S, Geddes D, et al. (2025). Nuts For Babies Study: protocol for a randomised controlled trial in Australia investigating if the risk of developing peanut and cashew nut allergies during infancy can be reduced by a high peanut and cashew nut maternal diet for the first 6 months of lactation. BMJ Open 15(10):e108137. — PubMed PMID: 41067762

PubMed Topic Searches

1. PubMed: Maternal diet in pregnancy and food allergy prevention
2. PubMed: Food allergens in breast milk and oral tolerance
3. PubMed: Early peanut introduction in infants
4. PubMed: Randomised trials of egg allergy prevention in infants

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Connections

• News Archive
• News, March 3, 2026 — an injection vs daily oral doses for children with several food allergies
• Food Allergy — causes, diagnosis and the research
• Peanut Allergy and Early Introduction — the LEAP trial and the change in infant advice
• Peanuts — the food, its nutrients and its research
• Peanuts: Nutrient Profile — what a serving of peanuts contains
• Eggs — the whole food and its research
• Eggs: Benefits Deep Dive — choline, eye nutrients and more
• Eggs: Nutrient Profile — what an egg contains
• Allergies — how allergic disease works
• Anaphylaxis — the most severe allergic reaction
• Eczema — a secondary outcome of the trial and a major allergy risk factor
• Immunoglobulins (IgG, IgA, IgM, IgE) — the antibodies behind IgE-mediated allergy
• Omega-3 Fats in Pregnancy — research on fish oil, pregnancy and the infant
• How Breast Milk Is Made — animation of milk production and let-down

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