The green fruit contains urushiol oil, the same substance found in poison ivy and poison oak which irritate the skin. You have to be very careful when removing the nut and it is for this reason that I have never purchased a whole, fresh cashew for myself and experimented with it. In an older article from Purdue University Horticulture I read that in some countries at one point the nut was simply thrown out with the fruit due to this toxin and much more emphasis was placed on the apple.
Cashews are grown in other tropical places throughout the world such as Vietnam and India. However, unless you live very close to one of those places it is likely you will never see a whole cashew. The fruit is juicy, fragile and spoils very quickly so extended transport is not an option.
I have grown to love cashew juice which is made from the cashew apple. It has a sweet flavor with a richness that resembles that of the nut. The tannins leave that familiar drying feel in the mouth which they are known for. This is the reason my husband does not prefer it, but for me it gives the juice a unique appeal.
I have noticed a difference in the juice when I order it in a restaurant versus purchasing it prepackaged in the store. I should mention that you can buy bottled pulp without sugar in the supermarket and add your own water and sweetener if desired. The fresher juice is much more astringent than the packaged.