When I was in grade school, I brought a PB&J sandwich to school 2-3 times a week. I never knew PB allergies existed. 35 years later when my kids were in grade school, they were not supposed to bring peanut material to school, including Pnut M&Ms for snack. When my wife worked in the HS office, there was one student who was transported to the hospital about once a month due to contact with peanuts. Why no allergies in the 1960s, yet allergies galore in the last 30 years.
From everything I’ve read over the years, I’ve always felt like the Hygiene Hypothesis, along with maybe some synthetic things being put in food and the environment are to blame:
This is not true.
There WERE food allergies (and other sorts) in the 1960’s. I date from that era and have had allergies all my life, all the way back to infancy (I required special baby formula because of it). One of my fellow students in early grade school suffered from dairy allergy of the sort where drinking milk meant an emergency trip to the hospital.
Some differences:
- They were probably not diagnosed as often as they should have been back then
- They were probably more rare
- It was legal for a school to bar the child with a medical problem if the adults involved thought that was easier/less troublesome than barring the offending substance. The same environment also meant you didn’t see vision/hearing impaired kids, wheelchairs, amputees, or other disabled kids in mainstream schools.
They were in fact much more rare. The relatively recent American Academy of Pediatric guideline that advised introduction of peanut containing foods between 6 to 12 months and sooner for selected individuals estimates that peanut allergy prevalence has tripled just since 1997.
Of note trends in infant solid food introduction had changed much from the '60s to the time of that guideline. In the '60 baby foods of a wide variety were introduced early but by the late '80s to '90s the trend became to hold off until later, and it became common in particular to hold off on the more allergy associated food until after 15 or 18 months. The concept was that it was known in animal models that no exposure until past critical developmental phases reduced allergies to those foods dramatically. But coincident with that food allergies increased.
Why? Real world was not the lab and there were repetitive small exposures that were unintentional and unknown, in both foods and skin products. Very small repetitive exposures sensitize the most. High repetitive exposures cause a suppresser response.
Short version - the wide spread trend over that time period to hold off on introduction of peanut containing foods until later toddlerhood seemed to be what triggered this explosion more than anything else and we will very likely see a decrease over the next decade as that trend reverses with the newer guidelines. Check in in a decade.
It clearly is not the complete story as other allergies and autoimmune conditions have also increased dramatically over that time (inclusive of celiac disease - real gluten intolerance). That’s where the hygiene hypothesis possibly comes into play (specifically the amount of antibiotic overuse both by providers and perhaps of greater import by the food industry).
There is no doubt that allergies existed decades ago. But the extreme deadly reaction, especially to PB, seems new. At least I had never heard of it until maybe the 90s. My WAG is that there is something new in the environment that explains most of it.
A lot of times it got blown off as being a fussy eater or just stubborn too. One of my brothers is allergic to chocolate. He breaks out in hives and his skin turns bright red. Yet growing up there were plenty of times when he got told he was just making things up or a little bit wouldn’t hurt him or the chocolate in cake is different from chocolate candy so eat it and don’t make a fuss.
The figures showing the increases in severe allergic reactions (e.g. anaphylaxis with shock) are sobering.
It’s across cultures.
Peanut allergy in specific may improve some with the new introduction guideance but there seems to be something more going on too.