Allergies/Evolution?

Sometimes I wonder if people with food allergies are just elite. I imagine that it is just an evolutionary advantage developed through centuries of realizing what is good for you and what isn’t. Think about it, your ancestors were so developed that they trained their throats to close up or throw food back up because they realized the dangers it may pose in the future. I am sure there are tons of studies on this type of thing and a logical answer, but I prefer to believe that the ancestors just snapped.