Peanut Mush In Infancy Cuts Allergy Risk. New Study Adds To Evidence

Mar 4, 2016
Originally published on April 12, 2016 10:42 am

Parenting can be an angst-ridden journey.

And one bump along the road is that horrible feeling that comes over you when you see your baby break out in hives after eating a particular food – say, peanuts — for the first time. (One of my three kids gave me that kind of scare.)

The concern is real. Between 1997 and 2008, the incidence of peanut and tree nut allergies nearly tripled, according to one published study.

Now, there's a growing consensus about how to prevent peanut allergies in kids who are at high risk. This includes children with a strong family history of food allergies and those with eczema.

Last year, a landmark study published in the New England Journal of Medicine found that high-risk babies who were fed a soupy, peanut-butter mush (starting between 4 and 11 months of age) were about 80 percent less likely to develop a peanut allergy by age 5, compared with kids who were not exposed.

"Giving peanuts very early on actually protected them from developing a peanut allergy," says Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Previously, parents of high-risk kids had been advised to delay the introduction of peanuts.

Now, a new follow-up study involving the same group of children adds to the evidence that, contrary to previous advice, early exposure can be beneficial.

Researchers followed the kids for one additional year. The kids were between 5 and 6 years old during this follow-up period. It turned out, these high-risk kids' tolerance to peanuts held up even if they stopped eating peanuts.

"A 12-month period of peanut avoidance was not associated with an increase in the prevalence of peanut allergy," the authors write in the paper.

This is an important finding, because it wasn't known whether the kids would need to maintain regular weekly consumption of peanuts in order to stave off developing an allergy.

"This new study is great because ... it looks like the benefit [of early exposure] is essentially permanent," says Scott Sicherer, a pediatric immunologist and allergy specialist at Mount Sinai Hospital. Immunologists will continue to study this.

Sicherer has helped develop new interim guidance based on the emerging evidence of the benefits of early, rather than delayed, introduction of peanut.

"There is now scientific evidence that health care providers should recommend introducing peanut-containing products into the diets of "high-risk" infants early on in life (between 4 and 11 months of age)," the consensus guidance states.

But that doesn't mean all parents should just rush in with the peanut mush. The guidance recommends that "infants with eczema or egg allergy in the first 4 to 6 months of life might benefit from evaluation by an allergist" — before they're introduced to peanut-based foods.

The evidence from the two studies together represents an important step forward in immunology, says Anthony Fauci. "It's a very important proof of concept," Fauci says.

And he says it's possible that early exposure will turn out to be a successful strategy to prevent other allergies as well.

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KELLY MCEVERS, HOST:

There is growing consensus about how to prevent peanut allergies in kids who are prone to allergies - expose them to peanuts early. A study published today in the New England Journal of Medicine supports a landmark study from last year. It found introducing infants to peanuts reduces the likelihood of developing an allergy. NPR's Allison Aubrey reports.

ALLISON AUBREY, BYLINE: Parenting can be an angst-ridden journey, and peanut allergies are on the long list of potential concerns for good reason. Between 1997 and 2008, the incidents of peanut allergies tripled according to one survey. So if you had a baby in recent years and you had a family history of allergies, you probably would not have fed your babe any food made with peanuts. Here's pediatric allergist, Scott Sicherer.

SCOTT SICHERER: So if a patient came to me with their baby who had eczema and an egg allergy, the last thing in the world we would've thought was to hurry up and give them peanuts because peanuts are an allergenic food.

AUBREY: But this thinking has changed rather dramatically. Last year came a big study. It found feeding high-risk infants peanuts in the form of a soupy, peanut-butter mush beginning at four-months cut the risk of developing an allergy by about 80 percent compared to infants who didn't get the mush. And now a follow-up study involving the same kids finds as the children hit kindergarten age, their tolerance to peanuts holds up even if they stop eating peanuts for a while.

SICHERER: This new study is great because it looks like there was a permanent change by their having had peanut early.

AUBREY: Sicherer is not involved in the new study, but he's been involved with the American Academy of Pediatrics in crafting new guidance. The guidance isn't official yet, but doctor groups are already recommending that parents of infants who may be prone to allergies introduce peanut-based foods between four and 11 months.

SICHERER: The guidance really is to start getting them onto peanut at that early stage before they would develop peanut allergy.

AUBREY: Though Sicherer says parents of high-risk infants may benefit from an evaluation with an allergist first. This change in thinking represents an important step forward, says Anthony Fauci, who directs the National Institute of Allergy and Infectious Diseases.

ANTHONY FAUCI: It's a very important proof of concept - the idea of training the immune system as it were not to respond adversely.

AUBREY: And he says it's possible that early exposure will turn out to be a strategy for preventing other allergies as well. Allison Aubrey, NPR News. Transcript provided by NPR, Copyright NPR.