A new study shows that certain formulas thought to lessen babies' chances of developing eczema and allergies actually don't fulfill that claim. Here's why.
How to feed your baby is one of the most important choices you'll make as a mother. And if you or other close family members have allergies, how not to pass them down to your child is probably a consideration. Certain formulas that contain broken-down cow's milk proteins have been touted as lessening babies' chances of developing eczema and other allergic diseases, which might make allergy-prone mothers more likely to choose them. But, a new study published in the journal The BMJ suggests that those claims are actually not true.
Researchers examined 37 separate studies with over 19,000 participants to see if infant formula that was "hydrolyzed," or contained broken-down milk proteins, reduced babies' risk of developing milk allergy, eczema, asthma and other allergic responses. "We reviewed all published literature on hydrolyzed formula and all allergy problems, as part of a project commissioned by the U.K. government to guide infant feeding advice," study author Robert Boyle, Ph.D., a pediatric allergist at Imperial College London, tells Fit Pregnancy. "We did not find any consistent evidence that hydrolyzed formula can prevent allergy problems."
So why did many of these studies claim the opposite? Allergic and autoimmune disease has been linked to early dietary exposure to cow's milk protein, so the thinking was that broken-down proteins would be less likely to trigger an allergic response. But when it came to actually proving this, scientists were not immune to the pressures of outside influences. "We found that few studies of hydrolyzed formula and allergy problems were of high quality," Boyle says. "In some there were clear conflicts of interest due to formula industry involvement, and in some there was evidence that the trial conduct may not have adhered to the international code of marketing of breast milk substitutes."
Boyle says that hydrolyzed formula is recommended for the prevention of allergies in high-risk babies by many professional groups, including the American Academy of Pediatrics. One formula, Gerber Good Start, even carries a "qualified health claim" on eczema prevention approved by the U.S. Food and Drug Administration (FDA) on its label. (However, the Federal Trade Commission brought a lawsuit against Gerber, claiming it misrepresented the FDA's position that there was "little to very little" evidence the formula could prevent allergies.)
Should you use these formulas?
Formula that is "extensively hydrolyzed," meaning the milk proteins are completely broken down, can help in cases of a diagnosed cow's milk allergy. "If an infant has an allergy to cow's milk and is not being breastfed, then switching [from regular formula] to an extensively hydrolyzed formula can reduce the milk allergy symptoms," Boyle says. (If an infant is breastfed, mom can eliminate dairy from her diet.) The issue is the claim that these formulas can actually prevent allergies. "Extensively hydrolyzed formula is useful when an infant already has cow's milk allergy," Boyle says. "But there is no good reason to think that breaking down proteins in milk would help prevent allergy problems from happening in the first place."
But even if these formula can't prevent allergies, they can't hurt, right? Not exactly. Boyle believes that the false claims could undermine a mother's efforts to breastfeed—if her baby is at risk for allergies, she might take into account that these formulas supposedly can prevent them when making a decision on how to feed her baby. "The World Health Organization recommends that children should be breastfed for at least two years," he says. "While there is no good evidence that this prevents allergy problems [either], it has many other benefits for a child's growth, development and health." If you are planning on breastfeeding, Boyle says taking a probiotic during the last month of pregnancy and while nursing could reduce baby's risk of eczema.
How to feed your baby is a very personal choice with many considerations—but it's important to have all the facts when doing so. Boyle hopes that professional recommendations will change to reflect the new information he's uncovered. "I don't think that guidance to use hydrolyzed formula is justified by the evidence," he says. "My view is that this recommendation should be removed from the guidelines."