I’ve been reading a lot about the alpha-gal allergy since my brother came down with it.
Part of what’s remarkable about that is that it’s the only dietary allergy to something other than a protien yet identified. And we haven’t been able to peg down an exact mechanism for how that’s possible, how it works, or how it results from a tick bite. Since it’s a carbohydrate, initially they didn’t think the alpha-gal itself was the allergen. Though that now seems likely.
Other non-dietary allergies often involve non-protien compounds. But allergies to compounds significantly simpler than protiens are vanishingly rare. And in terms of something as simple chemically as nitrates, or even amino acids (like glutamate, MSG being another proposed allergy of this sort) there really isn’t much in the way of a plausible mechanism for them to cause an allergy. Or even interact directly with our immune system. And both nitrates (or at least related compounds) and glutamate are things our bodies make themselves, and it’s a little impossible to be allergic to something you’re made of.
So again vis a vis the alpha-gal, you got a really weird one. It’s a much simpler sort of molecule than you normally see with allergies. And while humans don’t make it, we make some really similar carbohydrates. So it’s a really weird one, it doesn’t quite fit with what we know about allergies. But it doesn’t seem to undermine any of it either.
