In Israel this is done naturally by feeding children Bamba, a puffed peanut snack, at a very early age. Research shows significantly decreased levels of peanut allergy.
Bambas are recommended in the U.S. as well, but our kid entered anaphylaxis after eating just 5 bambas his first time, at about 6 months of age. It's certainly possible to have a peanut allergy despite early exposure. Recommendation in the U.S. is now for pregnant women to eat peanuts to expose the fetus in utero, but even this doesn't always work.
Kid is desensitized now after a year of oral immunotherapy, so add us to the chorus of voices saying "It works", but it can strike early and severely despite the parents' best efforts.
It's not just about early exposure to allergens, it's also early exposure to pathogens. There's a growing body of research that constant disinfection of hands and surfaces is what really caused the allergy outbreak. Humans need to prime their immune systems with exposure to pathogenic bacteria at an early age so that it can learn to fight them and not other substances which leads to allergies.
People mention this quite often to me because my toddler is on oral immunotherapy for peanuts, and there’s a small but important distinction here. It’s extra important when relatives start to think it’s okay to be casually leaving peanut products lying around within the toddler’s reach. (It’s not)
The general consensus among allergists is that early exposure reduces the chances of developing the allergy in the first place, but people on oral immunotherapy are still allergic, they just have a high tolerance and can still have anaphylactic reactions. Some will outgrow the allergy, but for peanuts most don’t and the data doesn’t yet exist for whether peanut oral immunotherapy increases the likelihood of outgrowing the allergy.
There are some early studies out [1] that indicate remission is possible with OIT. (For laypeople, "desensitization" ~= can tolerate some peanut exposure without a reaction, but still needs to carry an epipen and remain on the maintenance dose for life, while "remission" ~= no longer has a peanut allergy). The numbers were 71% desensitization and 21% remission for OIT vs. 2% both for a placebo. It was heavily dependent on age, with 71% of 1-year-olds, 35% of 2-year-olds, and 19% of 3-year-olds achieving remission.
Data will be scant at this time, because the full treatment takes a long time and needs to be adhered to closely. It's 30 weeks of OIT, followed by 2 years of a maintenance dose, followed by a 6-month hiatus to verify whether the maintenance dose can be stopped while still achieving remission, so data necessarily lags the start of any clinical trials by 3+ years.
I thought there was a study that suggested the weapon of first resort should be breastfeeding mothers eating the allergen-triggering foods so the kids get exposed to them indirectly.
Makes me wonder if there is something we should be doing with baby formula.
Yeah, we hadn't heard of this when our son was born, but the allergist mentioned it. When our daughter was born, we gave her something like this at his recommendation. The ones we got were some puffs that have a whole pile of allergens in tiny doses. Causation vs correlation and all that, and a small sample size, but our daughter doesn't have any issues with any allergies.
The economist Emily Oster wrote an excellent series of books about pregnancy anf early kid years, where she dives into details about various studies, whether they are causal, etc. It's one of the best practiacl explainations of reading research I've encountered targeted at non-academics, really well done. She has a chapter on peanut exposure allergies and i think inrecall that these early-exposure results are in fact from causal research vs just correlational research (basically there are at least two types of papers out thwre -- correlational and causal. As you might guess causal is harder to get for many reasons). Great books; she may also have published some chapters on her substack (substack came after the book I think).
I realize as I write this that you are probably saying that for your own experience you can't disentangle correlational from causation, to which I would say -- correct!
Emily Oster is a national treasure that is still flying under the radar for most people.
As above, she presents excellent science in an approachable manner for non-science minded folks. She also has enough of the technical details for this with the knowledge to be confident she has done a strong analysis.
If you are a parent and haven’t checked her stuff out, please do. (Zero affiliation or connection)
https://www.npr.org/sections/thesalt/2015/02/23/388450621/fe...