The documented benefits of nutritional intervention that might prevent or delay the onset of atopic disease are largely limited to infants at high risk of developing allergy because a parent or sibling has allergic disease, according to a revised policy statement of the American Academy of Pediatrics.
"Current evidence does not support a major role for maternal dietary restrictions during pregnancy or lactation," according to the new report. Therefore, physicians advising women on nutritional options related to allergies during pregnancy, lactation, and the first year of life can be less restrictive than they have been up to now.
"[Physicians] need to reconsider the entire issue of how they feed babies with the intention of preventing allergies," said Dr. Frank R. Greer, chairman of the American Academy of Pediatrics (AAP) Committee on Nutrition, which developed the statement in cooperation with the academy's Section on Allergy and Immunology.
The new document replaces a 2000 policy statement from the AAP that addressed the use of hypoallergenic infant formulas and included provisional recommendations for dietary management for the prevention of atopic disease (Pediatrics 2008;121:18391).
"The idea that egg, fish, and foods containing peanut protein should not be introduced before 1 year of age is not based on good science," Dr. Greer said in an interview. "I suppose that if I had a baby with severe eczema, I would not recommend those foods, but the problem is these restrictions have been applied to all babies."
There is evidence that breast-feeding for at least 4 months, compared with feeding formula made with intact cow milk protein, prevents or delays the occurrence of atopic dermatitis, cow milk allergy, and wheezing in early childhood.
In studies of infants at high risk of atopy who are not exclusively breast-fed for 46 months or are formula fed, there is modest evidence that the onset of atopic dermatitis might be delayed or prevented in early childhood by the use of extensively or partially hydrolyzed formulas, compared with cow milk formula, they said. However, not all hydrolyzed formula might have the same effect, and more research is needed to determine if the benefits extend to later childhood and adolescence.
Dr. Greer and his colleagues also concluded that there is scant evidence that delaying the introduction of complementary foods beyond 46 months of age prevents atopic disease.
Other statements summarizing the current evidence included the following:
PIMaternal dietary restrictions during pregnancy do not appear to play a significant role in the prevention of atopic disease in infants.
PIThere is no convincing evidence for the use of soy-based infant formula for the purpose of allergy prevention.
PIFor infants beyond 46 months of age, there is insufficient data to support a protective effect of any dietary intervention for the development of atopic disease.