Soy Formulas May Not Prevent Infant Allergies
Breast Milk Is Best for High-Risk Infants, Experts Say
July 22, 2004 -- Soy-based formulas are often recommended for infants with food allergies, but a review of past studies suggests they should not be recommended for the prevention of allergies or food intolerance in infants at high risk.
Although the evidence is not conclusive, the review suggested that formulas designed for infants with food allergies are a better choice for preventing allergies than soy-based formulas. At least one study comparing the use of these "hydrolysate" formulas with those containing soy found that the soy-fed babies were significantly more likely to develop allergies and eczema.
"Feeding with a soy formula should not be recommended for the prevention of allergy or food intolerance in infants at high risk (for these conditions)," researchers from the Westmead Hospital in New South Wales, Australia, write in the latest issue of The Cochrane Library Newsletter.
Breast Is Best
Four percent to 6% of children have food allergies, and a close family history is the best predictor of risk. A child that has two parents with food allergies has about a 75% chance of also developing allergies herself.
Although the researchers did not review studies that included breastfed babies, pediatric allergy experts contacted by WebMD say the best clinical evidence suggests that breastfeeding is by far the best choice for high-risk babies.
The American Academy of Pediatrics strongly recommends "exclusive breastfeeding as the hallmark for food allergy prevention" for at least six months. It further states that breastfeeding should continue for at least a year, although other foods should also be introduced after the sixth month.
"The best evidence that we have suggests that breastfeeding can help prevent food allergies in children at high risk," New York allergist Clifford Bassett, MD, tells WebMD. Bassett is a spokesman for the American Academy of Allergy, Asthma & Immunology.
"Breast milk is best for a lot of reasons, including providing complete nutrition and developing the immune system," he says. "It is important for mothers of high-risk infants to try and breastfeed."
In a joint report published last summer, the AAP and two European health groups addressed the issue of soy-based formulas vs. cow's milk-based formulas for preventing food allergies. The group noted that "studies of soy versus cow milk formula feeding in infants ... have not shown any prevention effect of soy on food allergy or atopic dermatitis." It concluded that there is "insufficient evidence to recommend soy formula feeding for primary food allergy prevention."