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
"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
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
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
"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
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."
Soy-based formulas contain the proteins found in soybeans
rather than those found in cow's milk. The two formulas contain almost
identical vitamins and minerals, and their nutritional values are similar.
There are three major hypoallergenic formulas:
- Whey-based hydrolysate formulas. The whey in cow's milk protein is broken
down or "predigested," making it less allergenic than the protein in
- Casein hydrolysate formulas have smaller protein products.
- Amino acid-based infant formulas, which contain protein in its simplest
form, may be recommended if an infant doesn't improve after a switch to the