Peanut Allergy Diagnoses Have Been Halved: What Did They Do?

Good news: it wasn’t “they raised the diagnostic criteria so that peanut allergy sufferers can be ignored”—which kind of switcheroo sometimes performed by institutions who are being hounded to lower their case numbers, which can be a problem for sufferers of a given malady, but more often the opposite is the case in the US, because after all, one has to diagnose a disease to sell a cure.

Bad news: there’s still a long way to go, because it was hoped to reduce the diagnoses by more than 80% (well: reduce the incidence, but scientists speak for what is measurable, so “diagnoses” is a good word to use here, since there could be cases going undiagnosed).

A LEAP of faith science

Not long back, doctors started telling parents something surprising: feeding babies peanuts early might actually prevent peanut allergies. Now, new research from the Children’s Hospital of Philadelphia shows this advice is working.

The shift began after the success of the huge Learning Early About Peanut Allergy (LEAP) trial in 2015, which found that introducing peanut-containing foods to high-risk infants between 4 and 11 months of age reduced their risk of peanut allergy by more than 80%.

That evidence prompted new guidelines—first in 2015 and 2017 for high-risk babies, and then in 2021 for all infants, recommending peanut, egg, and other allergenic foods be introduced between 4 and 6 months, unless the baby had already reacted to them. ← important to note!

So, how did that work out? Researchers (Dr. Stansislaw Gabryszewski et al.) investigated pediatric data of tens of thousands of children’s health records from across the US, and found:

❝The cumulative incidence and risk of development of peanut IgE-FA (0.79%–0.53%; hazard ratio [HR], 0.65; 95% CI, 0.55–0.77) and any IgE-FA (1.46%–1.02%; HR, 0.69; 95% CI, 0.61–0.78) decreased significantly (P < .0001) from the preguidelines to postguidelines period. Furthermore, the cumulative incidence and risk of development of peanut IgE-FA (0.79%–0.45%; HR, 0.55; 95% CI, 0.46–0.66) and any IgE-FA (1.46%–0.93%; HR, 0.63; 95% CI, 0.55–0.72) decreased significantly (P < .0001) from the preguidelines to postaddendum guidelines period. A decline in IgE-FA diagnosis postguidelines was confirmed in the interrupted time series analysis.❞

Translating from sciencese, we can say:

Since the guidelines were adopted, peanut allergy diagnoses dropped from 0.79% to 0.45% of children, and the rate of any IgE-mediated food allergy (i.e., any allergy that arises by the exact same mechanism as peanut allergies) fell from 1.46% to 0.93%.

That means for about every 200 infants exposed to allergenic foods early, on average one (life-threatening, and usually lifelong!) allergy will have been prevented.

For perspective: as there are about 3,500,000 children born per year in the US, that means each year, 17,500 fewer of them will have this crippling disability (it might not seem like a disability, because if you avoid peanuts you’re fine, but take a moment to think about the level of precautions you’d have to take not just with your own food, but that of people around you, and even what happens if someone you meet now ate peanuts earlier in the day and didn’t wash their hands as thoroughly as a surgeon—if a medical condition takes away your ability to engage with life normally, it is a disability).

You can read the paper itself here: Guidelines for Early Food Introduction and Patterns of Food Allergy

And in case you were wondering: Yes, adults can develop food allergies. Here are 4 types you need to know about

Want to learn more?

For much more detail than we can go into here, check out this excellent book that we reviewed a while back:

The End of Food Allergy: The First Program To Prevent And Reverse A 21st Century Epidemic – by Dr. Kari Nadeau & Sloan Barnett

It’s worth noting that with regard to the first-named author there, the bio begins:

❝Kari Nadeau, MD, PhD, is the director of the Sean N. Parker Center for Allergy and Asthma Research at Stanford University and is one of the world’s leading experts on food allergy❞

We mention this, because there’s a lot of quack medicine out there [in general, but especially] when it comes to things such as food allergies. So let’s be clear up front that Dr. Nadeau is actually a world-class professional at the top of her field.

Enjoy!