While it's true that eating pineapple may make your tongue experience a burning sensation, indulging in pineapple doesn't actually "eat" your tongue in any sort of manner that could be considered dangerous. That said, due to pineapple's acidic pH and bromelain, an enzymatic protein found in the fruit, some people may experience a burning or sore sensation in the mouth and tongue. This occurs because bromelain is a protease designed to break down other proteins. Your mouth contains proteins in its mucous lining, and when you eat pineapple, the bromelain may start to break down these proteins, causing a burning sensation. That said, unless you have an allergy to bromelain or to pineapple, in general, any burning you feel will be short-lived and your mouth will re-build its protective mucous lining quickly. You can try to avoid the sensation by rubbing the fruit with a little salt, eating it with dairy products, or cooking it. These all help activate and expend the bromelain before it reaches your mouth