[freedomben]

The stats that I've seen were at my allergist's office, so unfortunately I don't have a link. I'll definitely look for one tho.

What you say is very interesting. Cucumber (like citrus) was also not something that people really had allergies to until recently (or possibly your third possibility kicks in here). Peanuts and gluten have skyrocketed recently too.

Maybe off topic, but I read an interesting theory regarding the use of GMOs to explain this. The logic went basically like this:

Plants were genetically modified to be resistant to herbicides -> farmers began spraying fields indiscriminately, knowing that the plants they cared about wouldn't die, but the weeds would, therefore producing bumper crops much more regularly -> This led to one of two possibilities: 1. the chemicals are being consumed in unsafe quantities by humans now when they eat those plants or 2. the mutations that hardened the plants changed their protein structure such that they are less digestible, which leads to intestinal damage, which promotes intestinal permeability, which leads to food allergies to foods not previously a problem.