Turns out, there is a scientific reason you just can't get enough fromage in your face, be it in a classic grilled cheese sandwich , laid out atop a decadent cheese plate , or melted on a deliciously ooey, gooey pizza pie . Cheese is, quite simply, addictive because of the "casein-derived, morphine-like compounds" it contains, reports Thrillist Cheese might as well be called “dairy crack,” says Dr. Neal Barnard , founder and president of the Physicians Committee for Responsible Medicine. Your brain essentially reacts to it in the same manner it would to any addictive substance thanks to a protein found in dairy called casein, which is super concentrated during the cheesemaking process. So every time you break into the Brie, your body has to break down the casein it contains.Casein, like all proteins, is basically a bead-like string of amino acids. But when your body digests it, "the beads don’t entirely separate. Some of them stay attached in strings of four, five, or seven amino acids," explains Dr. Barnard . These shorter strings are the "casein-derived, morphine-like compounds" called casomorphins, and can attach to the opiate receptors in your brain. All that makes you crave another block of cheddar like a junkie in need of a fix, minus the shaking hands and general life-damaging behavior. (Assuming, of course, that you've never tried to sell off all your personal possessions in exchange for a block of Gruyere. Hey, no judgement here.)