Eating peanuts, eggs while breastfeeding has unclear impact on infant allergies

Key takeaways:

• Regular peanut consumption while breastfeeding provides infants with a regular source of peanut allergen to reduce sensitization and allergy.
• Lower maternal egg consumption during breastfeeding may reduce egg allergy but not egg sensitization.
• These results will inform the design of the current large-scale, multicenter PrEggNut study.

Whether a maternal diet rich in egg and peanut has any impact on allergies among infants during the first 6 months of breastfeeding remains unclear, according to a letter published in Pediatric Allergy and Immunology.

But the research did provide valuable pilot trial evidence to inform the design of the large-scale PrEggNut study, Debra J. Palmer, BSc, BND, PhD, head of the childhood allergy and immunology research team at the Telethon Kids Institute and adjunct senior research fellow at University of Western Australia Centre for Child Health Research, and colleagues wrote.

The parallel, two-arm, single-blinded and randomized Breastfeeding and Eating Nuts and Eggs for Infant Tolerance (BENEFIT) pilot controlled trial involved 109 pregnant women with singleton infants who had at least two family members with a medically diagnosed allergic disease.

The researchers randomly assigned 57 women to a high egg and peanut diet of at least six eggs and at least 60 peanuts a week, and 52 women to a low egg and peanut diet of up to two eggs and up to 20 peanuts a week, from birth through 6 months of lactation. Diets were assessed each month via a food frequency questionnaire.

During the 6-month intervention period, 80% of the women met the target for peanut consumption and 61% met the target for egg consumption.

With lactation consultant support, 76.6% of the infants remained breastfed at 6 months, including 14 who also received supplemental infant formula. Breastfeeding volumes varied from 10 mL to 750 mL per day with an average of 233 mL per day.

According to the researchers, 95% of the infants completed all the assessments at age 3, 6 and 12 months.

There were no significant differences in clinical outcomes between the high and low consumption groups. Seven infants developed an egg and/or peanut allergy, including three from the high group and four in the low group.

The researchers observed “interesting” but nonsignificant trends, including that a greater number of infants who developed a peanut allergy or sensitization were the low group and more infants who developed an egg allergy were in the high group, although no trends were noted for egg sensitization.

The researchers called their results consistent with their hypothesis that greater regular consumption of peanut during breastfeeding provides a regular source of allergen that helps infants develop tolerance, reducing sensitization and allergy.

But these results also potentially favor less egg consumption during breastfeeding to reduce infant egg allergy but not egg sensitization, the researchers continued. Calling for further investigation in larger trials, the researchers said maternal consumption levels of different food allergens may lead to allergen-specific outcomes among infants.

The participants in this study experienced lower-than-expected rates of food allergies, the researchers wrote, which they attributed to earlier introduction of allergenic foods into infant diets, exclusion of mothers with egg or peanut allergies from the study, and a 38.5% percentage of boy infants in the study population.

Although results for the first 6 months of breastfeeding were inconclusive, the researchers wrote, the BENEFIT pilot trial did inform the design of the current, large-scale, multicenter randomized controlled trial known as the PrEggNut Study.