How Sugars cause Allergies

I have to quote this directly from "Lick the Sugar Habit"

Every food we eat needs to be digested and metabolized by a variety of enzymes before it can be used by our cells. Enzymes will (not) work without the proper functioning minerals to help them out. If the usable minerals in the body decrease, such as in the presence of sugar, it is difficult for the body to digest anything in the small intestine because of the lack (or decrease) of functioning enzymes. Therefore, when you eat sugar, any food that is in the stomach at the time will become the food to which you can become allergic. This continued inability to digest a particular food eventually results in an allergy to that undigested, decomposing food.