The new types of food in Slash'EM are asian pears, mushrooms, sandwiches, tortillas, cheeses, pills and holy wafers. Mushrooms, pills and holy wafers all have special effects when eaten.
These are the possible effects of eating a mushroom:
Eating a pill has seven equally probable effects:
Holy wafers will cure sickness and lycanthropy. (Note that if you are a member of the Lycanthrope race, attempting to cure your lycanthropy will not work. You will ``feel very bad!'', lose 3-5 points of both strength and constitution, and have your HP reduced to a random number between 1 and 5 if they were greater than 10 and otherwise to 1.) If you are Lawful, eating a holy wafer will also cause you to gain 20-39 HP. If you are Chaotic, you will lose 10-19 HP, but it will not be fatal.
Two other edible items you may encounter are the Eye of the Beholder and the Hand of Vecna. Eating them is really not a sensible thing to do, and if you do it anyway, you will lose 150-199 HP.