Peanut allergies have doubled in prevalence in the last ten years in Western countries, and they're becoming more common in Africa and Asia, too. People have been trying to keep anything peanut related away from kids in response. Was that the right thing to do? ...No. This is Healthcare Triage News.

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In 2000, the American Academy of Pediatrics published a guideline which had recommendations to help decrease the risk of a child developing an allergic disease. They recommended, and I'm quoting:

"Mothers should eliminate peanuts and tree nuts (or almonds, walnuts, etc.) and consider eliminating eggs, cow's milk, fish, and perhaps other foods from their diets while nursing. Solid food should not be introduced into the diet of high-risk infants until 6 months of age, with dairy products delayed until 1 year, eggs until 2 years, and peanuts, nuts, and fish until 3 years of age."

In 2006, along with colleagues like my good friend Beth Tarini, we published a systematic review of the early introduction of solid foods in the later development of allergic disease. We found, somewhat to many people's surprise, that while there was some evidence linking early solid feeding to eczema, there was no strong evidence supporting a link between early solid food exposure and the development of asthma, allergic rhinitis, allergies to animals, or persistent food allergies.

In other words, there was no good evidence to keep infants away from foods in the believe that we could spare them food allergies later. Other studies showed a similar lack of evidence for the other parts of the recommendations. And in 2008, the American Academy of Pediatrics altered its recommendations to say that there wasn't good evidence to support food avoidance to prevent allergies.

A very recent study in the New England Journal of Medicine goes a step further. It says that keeping peanut proteins away from infants may be making things worse. To the research!

Researchers took 640 high-risk infants and randomized them to get peanut proteins or not for the first 5 years of life. They separated kids in both intervention groups by any preexisting sensitivity to peanuts. In other words, they kept track of kids in both groups who had an existing sensitivity to peanuts throughout the trial. And then they checked them at five years of age to see if they had a peanut allergy.

I have friends who already have lost their minds about this. I mean, letting kids get exposed to peanuts? Especially kids with a sensitivity to peanuts already? Insane, right? Until you see results like this.

Looking at all kids, about 3% of those exposed to peanuts developed a peanut allergy. Opposed to 17% of those who were not exposed to peanuts. If you only look at the kids without prior peanut sensitivity, about 2% exposed to peanuts developed a peanut allergy, as opposed to 14% of those not exposed. But in the cohort of kids with a known peanut sensitivity already, exposure to peanuts until 5 years led to a prevalence of allergies of 11%, versus 35% in kids not exposed.

In other words, exposing kids to peanut proteins, even those with a sensitivity, led to fewer allergies. Conversely, not exposing them led to more allergies.

I mean, kids with a previous sensitivity to peanuts, who were exposed to them, had a lower prevalence of peanut allergies at 5 years of age than kids who didn't have a previous sensitivity to peanuts, but were never exposed to them.

The accompanying editorial pulls no punches. They thought that the results of the trial were so compelling, and that the problem of peanut allergies so common and getting worse so fast, that new guidelines should be put forth soon. 

We're seeing an alarming increase in peanut allergies worldwide, and our response appears to be making things worse. Time to change our behavior here.

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