Can Food Allergies Be Prevented?

Maura Hohman

In 2000, the American Academy of Pediatrics directed parents to delay feeding their babies foods linked with allergies, such as milk, eggs and peanuts, until ages 1, 2 and 3 respectively. A decade later, the percentage of children with food allergies had risen by some 50 percent, and numerous studies have caused the group to pull back from the recommendation. Now, in the wake of new research suggesting that an early introduction to peanuts might actually be protective, the AAP, the National Institutes of Health and allergy research groups are on the verge of offering new guidance.

The new study, conducted by researchers in the UK and known as "LEAP" (for "learning early about peanut allergy"), was inspired by the observation that Israeli children, who regularly eat Bamba, a snack containing peanut butter produced in Israel, have fewer peanut allergies than children in the UK. Researchers divided 617 infants with a high risk of developing a peanut allergy into two groups, assigning one to avoid peanuts and the other to eat small quantities of Bamba starting between 4 and 11 months old until they turned 5. The group that ate peanuts was 86 percent less likely to develop an allergy.

The study's significance lies in its randomized, controlled nature, says David Fleischer, an allergist at Children's Hospital Colorado who is part of the committee creating the new guidelines. He expects them to be released by year-end. The reality is that the vast majority of kids won't get a food allergy, says Robert Wood, chief of allergy and immunology at Johns Hopkins Children's Center. But there are some 150 to 200 fatal food reactions in children each year, so knowing they could potentially lower the risk of an allergy should relieve parents.

A 2013 article written by a committee of the American Academy of Allergy, Asthma and Immunology may hint at what the new stance will be. In it, Fleischer outlined research indicating that once babies are successfully introduced to solid foods, parents should give them tastes of allergenic foods one at a time, waiting three to five days between introductions. (Peanuts can't be fed to infants, but a smidgen of peanut butter, perhaps mixed with cereal or fruit, can do the job.) The LEAP study, Wood notes, gives these recommendations more authority.

How can you predict whether your baby is among the tiny minority who will develop a food allergy? Having an allergic sibling means a child is seven times more likely to develop one than other kids, says Susan Raschal, an allergist at Covenant Allergy and Asthma Care in Chattanooga, Tennessee. Eczema and asthma indicate a higher risk, and some allergists think having a parent with a food allergy might make a child more susceptible. Parents of these kids should consult a doctor before introducing potentially problematic foods, Wood says. Allergists can launch a carefully controlled food challenge, giving the child the food in increasing doses in the office, with 15-minute monitoring periods in between. If he or she reacts to the food, the doctor will advise on techniques the parents can use to avoid the food and how they should respond to a severe reaction.

It's critical to know the signs of an allergic reaction. Look for hives, swelling around lips and eyes, coughing, wheezing, vomiting, red skin and a runny nose or other asthma symptoms.

"Twenty years ago, I'd say, 'avoid, avoid, avoid,'" says Alkis Togias, branch chief of the Allergy, Asthma and Airway Biology Branch at the National Institute of Allergy and Infectious Diseases. "But this strict approach does not seem to have worked." New guidelines should make it easier for hesitant doctors and concerned parents to make the leap.

Excerpted from U.S. News' "Best Hospitals 2016," the definitive consumer guidebook to U.S. hospitals. Order your copy now.