What Is Causing the Food Allergy Boom?

What Is Causing the Food Allergy Boom?

More people than ever before suffer from life-threatening food allergies. Will new research & treatments help reverse this trend?

Pictured Recipe: No-Nut Butter

Tara Mataraza Desmond remembers the sound distinctly: a small whimper from the crib of her 4-month-old, Miles, loud enough to wake her and her husband in the dark of night. Over the past months, Miles’s skin had become increasingly rough, blotched with rashy eczema bumps and in the mornings, his crib sheet would be mottled with bloodstains from the scratches his tiny fingernails would make as he itched. Desmond, a recipe developer and cookbook author, was nursing her twin boys at the time, and knew that eczema could be linked to food allergies. She thought, “This is from something I’m ingesting. I just felt sure of it in my gut.”

Several months later, when Miles was ready for solid food, Desmond sat him in his high chair, took a breath, and fed him a spoonful of plain, homemade whole-milk yogurt. Within minutes, his face looked like someone had smeared rouge all over it. She immediately sent a photo to her pediatrician, who confirmed it looked like a milk allergy. Desmond cut all dairy from both her and Miles’s diet, and brought him to an allergist, where he tested positive for life-threatening allergies to milk, egg, tree nuts, peanuts, sesame and sunflower.

No one else in the family—even Miles’s twin brother—had these allergies. “This was out of nowhere. It felt like a cruel joke from the universe for a food professional like me,” says Desmond. Since then, Miles, now 5, has taken three trips to the ER for accidental ingestion. “It terrifies me,” says Desmond, who shudders about the stories of children dying after being exposed to an allergen and not getting treatment in time. “It’s every parent’s worst nightmare that despite our best efforts to educate and prepare, one little slip-up with food could kill our child.”

The State of Allergies in America

This is the life that more than 4 million American children and their families live—and those numbers have been steadily increasing for decades, according to research published in the Journal of Allergy and Clinical Immunology. In 1999, 3.4 percent of kids had a food allergy; in 2011, the number jumped to 5.1 percent; and by 2015, it was 5.7 percent. The prevalence of peanut allergy alone more than tripled between 1997 and 2008. Even scarier: A recent insurance company assessment found that the number of claims related to anaphylactic food reactions—which cause the airway to constrict and can kill if not treated quickly—increased 377 percent nationwide between 2007 and 2016.

All this is not exactly news in an age where kids often aren’t allowed to bring peanut butter sandwiches to school, restaurants everywhere encourage customers to report allergies, and the question parents automatically ask before play dates is, “Any allergies we need to know about?”

The million-dollar question is: Why is this happening? What has changed so drastically to trigger this widespread problem? Researchers have several ideas, but one of the most controversial theories involves the fact that the old infant-feeding guidelines turned out to be 100 percent wrong. “There was certainly a problem before the guidelines happened. But they didn’t stem the tide,” says Kari Nadeau, M.D., Ph.D., director of the Sean N. Parker Center for Allergy and Asthma Research at Stanford University. In fact, they may have made the growing problem even worse.

Allergy Guidelines Gone Wrong

Food allergies used to be rare. Even as recently as the early 1980s, few children had them. But in the 1990s, more and more kids’ immune systems began overreacting to everyday foods—a chain reaction that begins when food proteins bind to immune molecules in the body called IgE. Those IgE molecules then attach to other immune cells that spurt out histamine and other inflammatory chemicals, and can very quickly cause a life-threatening anaphylactic reaction that must be promptly treated with the epinephrine from an EpiPen.

In response to this upswing, the American Academy of Pediatrics released recommendations in 2000 advising new moms to breastfeed exclusively until their babies were at least 6 months old, and if their infants were “high risk” for food allergy (those with a family history) to avoid common triggers such as peanuts and tree nuts, and consider eliminating cow’s milk, eggs, nuts and fish (the proteins are passed on through breast milk). Parents were also told to delay giving high-risk kids dairy products until age 1, eggs until age 2, and peanuts, nuts and fish until age 3.

Often, however, pediatricians gave this advice to all parents, not just those with infants at risk. The guidelines came with the following caveat: “Conclusive studies are not yet available to permit definitive recommendations. However, the following recommendations seem reasonable at this time.”

If these guidelines seem rather Draconian, they were. Parents had to bend over backwards to avoid these foods, both in their own diets (for nursing moms) and their child’s. Yet they were based almost entirely on “expert opinion,” not solid research. “Not unlike a lot of guidelines at the time, there were people who sat around in a room and, based on what they thought, made decisions and developed recommendations,” says researcher Wesley Burks, M.D., executive dean of the University of North Carolina School of Medicine.

They surmised that delaying the introduction of these allergens would give an infant’s immune system time to mature and respond normally when finally exposed to the food—preventing allergies from occurring. This idea was based partly on research in mice, and on some observational studies showing that when mothers nursed exclusively and avoid allergenic foods, it led to less eczema, which is linked to food allergies.

Experts had the best intentions, but were working with limited data. Despite the fully acknowledged uncertainty of these recommendations, pediatricians all over the country—and world—began counseling parents to avoid feeding allergens to their babies.

The Shifting Science

But by 2010, the science of immunology had evolved dramatically—a lot more research had been conducted and a clearer picture of how allergies work had emerged—and experts began to think that waiting to introduce allergenic foods might not be so helpful after all. A panel convened by the National Institutes of Health revised the recommendations to say that, in general, there was probably no need for infants beyond 4 to 6 months to steer clear of common allergens. This was, again, based largely on “expert opinion.”

Then, in 2015, everything changed. British researchers had noticed that Jewish children living in the United Kingdom were 10 times more likely to develop peanut allergy than Israeli children of similar ancestry. One reason they thought this might be is that in Israel, parents freely give their babies peanut products, usually by 7 months of age.

To determine whether this early introduction of peanuts could be protective against allergies—rather than promote them—they conducted a trial called Learning Early About Peanut Allergy (LEAP), recruiting 640 infants between 4 and 11 months who were considered high-risk for developing the allergy. The babies were split into two groups: one that regularly ate a peanut snack called Bamba, and another that wasn’t exposed at all. Five years later, the peanut-eating group had 86 percent fewer cases of peanut allergy than those who avoided them.

This landmark study stunned the world. “LEAP was a game-changer because it proved through a randomized, controlled trial that it was better to eat peanuts early and often to decrease the likelihood of developing an allergy,” says Nadeau. “It flew in the face of the mantra that we should avoid them until 2 or 3 years of age.”

In 2017, based primarily on the LEAP findings, the NIH panel published new guidelines for peanuts that completely flipped the script—recommending that kids with an elevated risk (including those with severe eczema or an egg allergy) start eating foods containing them around 4 to 6 months of age, as long as they were given the go-ahead from an allergist first. There has been no formal update for other allergens, but it was a big lesson learned. Recent research estimates that early exposure to peanuts and other foods could prevent tens of thousands of kids from developing allergies, and perhaps stall, if not reverse, the trend.


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