My question is why are there only a few notorious allergic reactions but not a broad spread of people allergic to this or that?
We hear about nut allergies all the time. Touch a peanut and drop dead. Yet I have never heard of a broccoli allergy.
Why? What makes a peanut special versus (say) a carrot?
Broccoli hurts me to eat it. Happened suddenly after a procedure in hospital.
Couldn’t eat it anymore. I’ve tried small amounts a couple times. No go.
I can’t say it’s an allergic reaction. But it does cause GI issues. Mainly pain.
I think the answer is gonna be eosinophilic.
Peanut allergies appear to be primarily a reaction to certain proteins in peanuts, and the reaction becomes even more severe when the peanut is roasted.
Also, nuts, and peanuts, have a particularly high number of known food allergens.
Moderator Note
This is in FQ. Please hold off on personal experiences and guesses until the question has been addressed factually.
I don’t know the full answer, but I do know that foods that tend to cause allergies are also foods that have proteins that are not as easily broken down into simpler proteins that your body considers to be safe. This makes it easier for your immune system to identify those proteins, and therefore easier to mis-identify them as a threat.
As to why your immune system triggers on those proteins in the first place, that is beyond my knowledge.
Yet, a quick goggle search indicates they exist as do allergies to carrots. They’re just pretty rare. You as an individual can be allergic to damn near anything.
I think kenobi_65 pretty much nailed it. Randomly peanuts just have a greater than normal number of potential allergens including some that cannot be deactivated by heat. Why they have a greater number of potential allergens is a question best asked of a putative deity. Sometimes humans are just more commonly reactive to one thing than another.
Take urushiol. There is a wide variation in response. Some modest minority of people are highly resistant, but most people are mildly to severely allergic to the stuff. Which makes humans actually quite weird relative to the rest of the animal kingdom. Because the vast majority of birds and mammals are completely unbothered by it. Most browsers like deer and goats love poison oak - for them it is a tasty salad ingredient. So do birds. I always get a kick out of taking pictures of birds perched on it or even happily eating poison oak seeds. Urushiol does not seem to have been an evolutionary response to predators, but more likely developed as an antimicrobial defense. That humans, probably primates generally and, even more randomly guinea pigs, are allergic to it just seems to be down to the bad luck of the evolution dice roll. Some have hypothesized that it may be down to the fact that both primates and guinea pigs cannot natively synthesize vitamin C, but I believe that is unproven and contact dermatitis on the occasional dog isn’t explained by that. Might as well ask dogs why chocolate is potentially death or cats why onions are likewise. Some species are just randomly more sensitive to one environmental hazard than another.