Food Allergen Avoidance in Pregnancy May Decrease Risk of Allergy Development in Offspring

Deborah Brauser

March 08, 2010

March 8, 2010 (New Orleans, Louisiana) — Dietary avoidance during pregnancy and later by mothers of children with food allergies can reduce the development of peanut and egg sensitization and asthma symptoms in subsequent offspring, according to a new Australian study presented here at the American Academy of Allergy, Asthma and Immunology 2010 Annual Meeting.

"In highly motivated, high-risk families, allergen avoidance can be very effective," said lead author Velencia Soutter, MD, consultant pediatrician in the Allergy Unit at Royal Prince Alfred Hospital in Camperdown, Australia, during her late-breaking research presentation.

"This study came about because parents were begging us for help," she later explained to Medscape Allergy and Clinical Immunology. "Once they have 1 child with a food allergy, they want to know what they can do to avoid having their next child go through those same struggles."

Dr. Velencia Soutter

Lower Peanut, Egg Sensitization in Avoidance Group

In this study, the investigators assessed 274 families with children with significant food or airborne allergies and with moms who were pregnant again. During the last 3 months of pregnancy, through lactation, and into the second year of life for the infants, these mothers were encouraged to avoid foods such as peanuts, tree nuts, milk, and eggs as part of an avoidance strategy.

"Peanuts and tree nuts were especially important because there is a high risk of allergies to these things becoming life long," explained Dr. Soutter.

The avoidance strategy, which was selected by mothers of 202 subsequent children, included education and advice on nutritional compensation due to cutting out milk. The mothers of 111 other subsequent children chose to not practice avoidance. All children were followed up at 18 months, with a smaller number followed up at 3 years of age (avoidance, n = 73; nonavoidance, n = 44).

Dr. Soutter and her team performed skin prick tests for 12 allergens and assessed eczema and asthma symptoms in all of the children.

Results showed that the children from the avoidance group had a significantly lower prevalence of peanut sensitization at 9% compared with 37% for those in the nonadvoidance group (P < .001) and a lower prevalence of egg sensitization (23% vs 50%, P < .001) at the 18-month mark.

The results at 36 months were similar at 16% vs 52% and 34% vs 75%, respectively.

"The children were also significantly less likely to develop symptoms of asthma at both time points [9% vs 23% and 11% vs 43%]," reported Dr. Soutter.

Although the rates of dust mite sensitization and eczema were both reduced at 18 months for the avoidance group compared with the nonadvoidance patients (14% vs 24% and 49% vs 62%, respectively), the rates for these measurements were not significantly different between the groups at 36 months.

"Early allergen avoidance can prevent the development of food allergies and may have an impact on later development of allergic disease," summarized Dr. Soutter.

"For people who are desperate for help, it is possible to make a difference," she added. "However, there's no guarantee. Despite our best efforts, some children did become sensitized. It's very hard to make general recommendations based on our findings, but I think that we are in a position where we can say that what you're doing does modify the outcome."

Dr. Soutter reports that her team next plans to look at gut reactions in relation to dietary changes. "We've put a lot of people onto an elimination diet, and so we're interested in what happens to the gut flora in those patients, especially in children."

Conflicting Data

"This study is interesting because it conflicts with other data coming out right now that if you [practice avoidance] too early, it's bad, and if you wait too long, it's bad," said session moderator Jonathan M. Spergel, MD, PhD, associate professor of pediatrics at Children's Hospital of Philadelphia, Pennsylvania.

"This study's data looks wonderful, but there are a lot of questions with it, a lot of 'I don't knows' and 'I'm not sures', especially because there weren't uniform preventions performed," added Dr. Spergel, who was not involved with the study.

"Overall, I'd say that it's another paper to consider when we're giving advice to our patients because the current recommendation is that we don't know what's right. It's really something else to consider as we try to evaluate the correct recommendations to give to parents," he concluded.

Dr. Soutter and Dr. Spergel have disclosed no relevant financial relationships.

American Academy of Allergy, Asthma and Immunology (AAAAI) 2010 Annual Meeting: Abstract L9. Presented March 2, 2010.


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