by Erin Child
Do you like peanut butter? So do I. I’m kind of obsessed. Perhaps you add it to your smoothie bowl, drizzle it artfully on your Instagram worthy oatmeal, or, if you’re in grad school, it’s part of your PB&J. After all, that is the cheapest, easiest thing to make. But what if you had to take the PB out of the PB&J, and eliminate it from your diet and your life? This is a growing reality for many in the United States, with outdated, misinformed guidelines being blamed for the recent spike in peanut allergies. Read on to explore the revolutionary research that has spurred the creation of new guidelines, and why Americans need to change how we handle peanut exposure in childhood.
I recently stopped eating peanut butter in any way that could be deemed pretty or practical. Instead, you can find me in my room, with the door shut, maniacally shoveling peanut butter into my mouth with a plastic spoon.
This all started at the beginning of 2017. No, it is not some bizarre New Year’s resolution or diet trend. Rather, a new roommate moved in. She’s a great girl – kind, thoughtful, willing to learn how to properly load a dishwasher – and massively, catastrophically allergic to peanuts. She is also allergic to tree nuts and soy, but peanuts are THE BIG BAD. They are the reason why I spent the week before her arrival scrubbing my kitchen from top to bottom and running every dish and utensil (even the wooden ones, to my chagrin) through the dishwasher. And there is now an EpiPen® in our kitchen. Just as they are on some airlines, peanuts are now banned from the general living areas of my house, and thus I & my beloved jar of peanut butter have been sequestered to my room.
Many of you have probably dealt with peanut-free schools or day cares, or been informed to not consume any peanut products on your flight. Peanut allergy rates in children in the United States have quadrupled from the late 1990s (less than 0.5%) to about 2% today, and are the leading cause of anaphylaxis or death from food allergies. Thanks to my new-found awareness, I have become extremely self-conscious about eating peanut butter in public spaces. On the bus the other day some peanut butter dripped from my sandwich to the seat. I panicked, thinking “What is the chance this spill is going to wind up hurting some little kid?” (I hope they are not licking the seats on the bus, but still.)
Coupled with my new roommate’s arrival, I was fascinated to find that peanut allergies have been back in the news. On January 5th, 2017, the National Institute of Allergy and Infectious Disease (NIAID) published new guidelines for practitioners about when to introduce peanuts to high-risk, medium-risk, and low-risk infants. High-risk infants with severe eczema and/or an egg allergy should be introduced to peanuts between 4 to 6 months. Medium-risk infants with mild eczema should be introduced to peanuts by 6 months, and low-risk infants without eczema or other allergies can be introduced to peanuts any time after they have been introduced to solid foods.
These guidelines fit in with the dual-allergen exposure hypothesis. This suggests that children are first exposed to food particles through their skin as infants. This exposure primes their immune systems to treat the food proteins like invaders and build up defenses against it. If the food is eaten years later, the child has an acute allergic reaction because their immune system had ample time to prepare. Children with eczema have weakened skin barriers and are much more likely to experience repeated skin exposure to food allergens. This leads to an increased chance of an allergic reaction once they eat the food. Current research now supports this hypothesis, and also suggests that by shortening the time between skin exposure and ingestion, we will reduce the number of acute allergic reactions. The sooner an infant starts eating an allergen, the more likely the body will adjust to it without having time to bsuild up strong defenses against it.
These new guidelines on peanut exposure from NIAID seek to correct for guidelines set by the American Academy of Pediatrics in 2000. The 2000 guidelines were based on only a few tests done on hypoallergenic infant formula feeding, yet conclusively recommended that infants at high-risk for peanut allergies wait until 3 years of age to first try peanuts. Based on the newest findings, it appears that this advice was ill advised. My roommate, n=1, was born in the mid-1990s when delaying peanut exposure was coming into vogue. She had severe eczema an infant, and following doctors’ recommendations, wasn’t introduced to peanuts until somewhere between 18-24 months old. She is equally fascinated with the new research, and wishes there was some way to know if the outcome would have been different had she tried them at a younger age.
Peanut allergies are more common in the US, UK, and Australia, which are also the countries that have historically had the most stringent recommendations around peanut introduction. As doctors and researchers sought to figure out why peanut allergies were ballooning, they looked to countries with very low peanut allergy rates, like Israel, where infants are introduced to peanuts at early ages. In Israel, instead of Cheerios, infants are given a peanut based snack, called Bamba, as one of their first foods. In other developing countries, infants are exposed to peanuts early on—both in their environment and in their food. These other countries also have much lower allergy rates.
In 2015, NIAID funded the Learning Early About Peanut Allergy (LEAP) study to determine whether early exposure to peanuts would decrease the incidence of peanut allergies. The UK study was a randomized controlled trial including 640 infants between 4 and 11 months of age with severe eczema and/or egg allergy. The infants were split into two groups (based on skin prick test results for peanuts) and then randomized to either eat or avoid peanuts until 60 months old (5 years). For infants in the negative skin prick test group, 13.7% of those who avoided peanuts had developed an allergy and only 1.9% of those who ate peanuts developed an allergy (P<0.001). For infants in the positive skin prick test group, 35.3% who of those who avoided peanuts had developed an allergy and 10.6% of those who ate peanuts developed an allergy (P=0.004). These results were significant and stunning, prompting the formulation of the current NIAID guidelines.
So, should we all start slathering our babies in peanut butter? Maybe. (As always, talk to your pediatrician). Food allergy science is an evolving field, and what is true today may not hold true a decade down the line. But based on the significance of the current research and the lower peanut allergy rates in cultures and countries that do not limit peanut exposure, the evidence strongly indicates that parents in the United States should change their approach.
Only 20% of children diagnosed with peanut allergies will grow out of them. The vast majority, like my roommate, are allergic for life. For now, research on reducing peanut allergies in adults is limited, making it unlikely that we will be eliminating any allergies anytime soon. So for now, I will continue to eat my peanut butter in my room. Alone.
Erin Child is a second semester NICBC student in the dual MS-DPD program and this is her first article for the Sprout. She loves cooking (usually with Friends or Parks & Rec on in the background). She hates brownies. (Seriously.) As the Logistics Co-Chair for the Student Research Conference, she looks forward to seeing everyone there on April 8th!