Peanut, Egg, and Milk protein (CMPA) allergies are common in babies. My understanding is that the digestive system is not mature enough to process them, so it rejects them. Some of these allergies develop even while breast fed (baby colic). I take that some allergies stick once developed. But you should consider that something that creates an allergy response in a baby may be not harmful at all for an adult. And sometimes, once the allergy is triggered it sticks.

I wonder why they weren't common 30 years ago. Not a single person in my entire family from my generation and before has a single allergy, nor was it ever a big thing in school I attended in various US states in the 90s and early 00s.

It's like between the time I went to college and my own kids started school, they exploded and now all of the sudden a PB&J sandwich isn't allowed in school. That would have been unfathomable to me in my youth.

Its untrue, peanuts and milk allergies were very common 30 years ago, probably more than now in percentage. My genetic grandmother can't eat most of processed food without having an allergic reaction. Probably people were a bit ashamed of their non-threatening food allergies (most food allergies just give a lot of gas and small stomachaches).

Also related, Distilbene did not only wreck fecondity, it gave a lot of children food allergies, and i'm pretty sure distilben distribution stopped in the late 70s, so maybe we should just get the numbers and compare, but i'd bet food allergies were more prevalent in the 80s.

Interesting, I might have been in a bubble then. My parents and their generation immigrated to the US from a developing country, much poorer, but in all of our family gatherings, there was never a concern for allergies. And we use basically everything in our cooking.

I specifically remember weddings and whatnot when snacks were given out to everyone that there was no hesitation in offering anyone else's kids food for fear of them having an allergy.

I wonder then what the catalyst was for schools banning nuts and airlines no longer serving peanuts. Assuming people were always allergic in similar or higher proportion with similar severity, was it simply changes in the political winds?

It's because

(1) the internet and social media means you know about far more people with allergies than before,

(2) you are a adult and not a child, so you know more people now

(3) institutions have adopter broad inclusionary policies even if no one with an allergy is present

(4) institutions are being far more careful now (you eating a your granola bar poses no significant risk to someone with a peanut allergy, but it's still banned sitewide).

I asked my parents about this, and they said that peanuts weren't common back then - they were expensive and a luxury so as a result we didn't have such widespread visibility of the problem.

Allergies where common 30 years ago, but you are right about the percentage of people that have allergies is raising and getting more severe. You can even find references to allergy going back to Aristotle's time, so not exactly a new thing. I haven't got a link to it, but did take a webinar on allergy some weeks ago.

None know exactly why where are getting more allergic, but since allergy most often is the immune system attacking harmless things some theories is that we have to clean an environment in our homes.

I think that the immune system "correlates" them with other harmful substances which are sometimes but not always present. The number of possible culprits is long: pesticides, random cleaning products used on the processing equipment, sometimes mold can grow on peanuts if they're stored improperly, the list goes on.

Our immune systems are in many ways similar to police forces, and if they hear "a problem being reported" often enough while peanuts are around, they may just bunch them together with the offender.

The problem is compounded by a dirty baseline environment. In the early stages, the immune system is "primed" with a "baseline" of what should and shouldn't be there, but if the VOCs and such are already there, it just learns that they are OK and doesn't react to them.

I attended school in the late 90s early 2000s (in canada).

It was a big deal then, there were kids i knew who were deathly alergic to peanuts.

Severe allergeries seem to be on the rise but i think your timeframe is wrong.

I went to to 8 different schools between K to 12th grades in 6 different states, and I don't recall meeting anyone who was deadly allergic to anything. I'm pretty sure I didn't even learn about epipens until maybe later in high school or possibly college.

The only ailment in kids that I think I had heard of was asthma, for which people had inhalers.

Of course, my data is weak and anecdotal, but based on the fact that a staple American food isn't allowed in schools anymore, I assume something must have changed.

Attending K-12 in the late 80's/early 90's I didn't know anyone with a serious allergy in school. There was never any concern about peanut butter food/snacks, or anything like that. A few kids with inhalers, that was it.

Allergy != Intolerance. When you have an allergy, you suffocate, when you have intolerance to something, it'll be unpleasant to be around you and you may spend some time on the toilet. This is an oversimplification, but one is an immune reaction and the other isn't. Inability to digest something to me sounds like neither of those cases.

This is an oversimplification. An allergy will not necessarily cause anaphylaxis (suffocating, etc). I'm allergic to a lot of types of pollen/mold/dander (skin prick test) and also two food items, also identified with a skin prick test, and I've never yet had anaphylaxis. When I eat oatmeal/rye (my food allergies) I get a runny nose, fatigue, and mild GI distress.

Forgot to mention, I also have lactose intolerance. I think I have a bit of gluten intolerance too, but that might be psychosomatic and I haven't yet had a family member help with a blind study on myself. Sometime I intend to.

The main point was that failure to digest something doesn't mean that you are allergic or intolerant. My impression was that this was what the example with babies' bodies "rejecting" some foods that they cannot process implied. Humans can eat stuff they cannot digest (fiber, corn kernels without chewing, anyone?) without adverse effects, stuff will just pass through. Unless you're eating nails or glass, but that's a mechanical damage...

Peanuts are a great example. I am not allergic to peanuts myself, but I avoid eating them.

I don't know why people become allergic to them, but there must be something in some peanuts which sets off their immune system.

The true irony of this statement, and I want to emphasize I am not a doctor, is that you are more likely to cause a peanut allergy by avoiding it!

https://directorsblog.nih.gov/2017/01/10/peanut-allergy-earl...

Similar to germ theory, some exposure is actually good.

From my understanding, some types of exposure promote allergy while other types of exposure prevent it.

That's not how allergies work. People with allergies get an immune reaction to a harmless compound.

This assumes that if your immune system reacts negatively to something, it is guaranteed to be actually harmful to the body.

If our immune systems and bodies were all-knowing and perfect, then sure, that would be a valid assumption, but they're far from it.

How far do you take that theory? People have allergies to many (normally) benign substances. Melons, natural latex, ibuprofen, pollen, etc.

Generally speaking, if it wasn't in my ancestors' environment, I avoid it. Otherwise, approach with caution.

Nature can be dangerous, too, but at least it's likely that someone in the past has dealt with it and lived to reproduce.

With new synthetic substances, you're essentially doing alpha-testing with your irreplaceable hardware/software system...

Pollen in particular is weird because simply being outside should expose you to some level of pollen, compared to foods like melons or peanuts that may or may not be part of your diet. I'm mildly allergic to dust mites and they're literally everywhere.

Right. I'm currently undergoing allergy immunotherapy, so back in October I had a battery of allergy tests.

Turns out I'm allergic to some trees, some grasses, pollen, mold, dust mites, and a bunch of other things. And yet my childhood from a very young age was filled with playing outside in the yard and and in the woods.

Also my family had (indoor-only) cats since before I was born. My parents were allergic to them, and my sister and I are also allergic. (Wanting to get a cat is what prompted me to start the allergy shots.) So I've been exposed to cat dander since I was an infant. And yet: allergic. Some things are just hereditary, I guess.

I'm sure there are some cases where not being exposed to something when young can cause you to develop allergies, but that's definitely not the only cause. Seems like there is definitely a genetic component that can moot any amount of childhood exposure.

Yes, peanut proteins.