New evidence guides parents on pregnancy diet and allergy prevention
A landmark Australian study, co-authored by Nepean Hospital’s Clinical Director for Women and Children’s Health, Professor Ralph Nanan, has found that eating higher amounts of eggs and peanuts during pregnancy and breastfeeding does not reduce the risk of food allergy in infants.
Published in the New England Journal of Medicine (NEJM), one of the world's most prestigious medical journals, the PrEggNut Study is one of the largest food allergy prevention trials ever undertaken.
The research investigated whether exposing babies to increased amounts of egg and peanut proteins before birth and through breast milk could help prevent the development of food allergies during infancy.
More than 2,100 pregnant women from across Australia took part in the trial. All participants were carrying babies considered at increased risk of allergy due to a strong family history of allergic disease.
Researchers compared mothers who consumed a diet rich in eggs and peanuts, including at least six eggs and 60 peanuts each week, with mothers who followed a standard diet containing lower amounts of these foods. The dietary intervention began before 23 weeks of pregnancy and continued until four months after birth during breastfeeding.
When infants were assessed at one year of age, researchers found no significant difference in allergy outcomes between the two groups.
Approximately eight per cent of infants in both groups developed an egg or peanut allergy, indicating that higher maternal consumption did not reduce the likelihood of developing food allergy.
“Food allergy prevention is one of the most important challenges in allergy research, and there has been considerable interest in whether changing a mother's diet during pregnancy and breastfeeding could influence a child's allergy risk,” says Ralph.
“Our findings provide clear evidence that increasing egg and peanut consumption during this period does not reduce the likelihood of food allergy developing in infancy.”
Scientists have long suspected that exposure to food proteins in the womb and through breast milk may influence a child's immune development. While previous observational studies suggested a possible benefit, high-quality evidence from large randomised controlled trials had been lacking.
Importantly, the higher intake of eggs and peanuts was found to be safe for both mothers and infants, with no meaningful differences in serious adverse events, hospitalisations or allergic reactions between the groups.
The findings also reinforce existing evidence supporting the introduction of common allergenic foods such as egg and peanut directly into an infant's diet during the first year of life, which remains a key strategy for food allergy prevention.
“This study helps answer a long-standing question for clinicians and families,” says Ralph.
“High-quality evidence is essential for developing effective prevention strategies, and these findings allow us to focus future research efforts on approaches that are more likely to improve outcomes for children.”
Food allergy affects thousands of Australian children and remains a significant public health concern. Australia continues to have some of the highest rates of food allergy worldwide, making effective prevention strategies a major research priority.
Publication in the New England Journal of Medicine highlights the international significance of the research and its contribution to evidence-based allergy prevention strategies.
“Food allergy continues to affect a growing number of children worldwide, so identifying what works, and what doesn't work, is equally important,” says Ralph.
“By providing definitive evidence in this area, the study helps inform clinical guidelines and supports families in making evidence-based decisions during pregnancy and early childhood.”
Full findings from the study are available in the New England Journal of Medicine.