Eating more eggs and peanuts during pregnancy does not prevent infant allergies, new trial finds

A recent study published in the New England Journal of Medicine shows that increasing maternal intake of eggs and peanuts during pregnancy and breastfeeding does not significantly reduce the risk of food allergies in infants, challenging previous preventative strategies.

A new clinical trial suggests that eating more eggs and peanuts during pregnancy and breastfeeding does not lower the chance that infants will develop allergies to those foods. Researchers reported in the New England Journal of Medicine that the strategy made no meaningful difference in allergy rates at 1 year of age.

The study followed 2,137 pregnant women whose children had a family history of allergic disease. According to the journal, participants were assigned either a diet that included at least six eggs and 60 peanuts a week, or a standard intake of no more than three eggs and 30 peanuts weekly. The trial began before 23 weeks of pregnancy and continued through four months after birth during lactation.

At 1 year, 7.8% of infants in the higher-intake group and 8.4% in the comparison group had immunoglobulin E-mediated egg or peanut allergy, a difference that was not statistically significant. Safety outcomes were similar in both groups, the researchers said.

In an accompanying editorial, Maria C. Jenmalm of Linköping University said the findings show that the key period for food allergy prevention is not simply expanded by increasing maternal intake of these foods. Her comments fit with earlier evidence that has pointed more strongly towards early infant exposure. The LEAP trial, also published in the New England Journal of Medicine, found that introducing peanuts early in high-risk infants reduced peanut allergy compared with avoidance. Other research has suggested that maternal probiotic use and fish oil may affect some allergy outcomes, but avoidance of allergenic foods during pregnancy has not been shown to help.