U.S. researchers recently discovered that caffeine prevents rats from developing a disease similar to multiple sclerosis in humans. This finding will help develop new ways to combat multiple sclerosis. Jeffrey Mills and others at Cornell University found that rats that consumed a certain amount of caffeine per day (equivalent to 6 to 8 cups of coffee per day for a person) were less susceptible to experimental autoimmune encephalomyelitis, possibly as a result of caffeine preventing immune cells from entering the central nervous system of the rats. Experimental autoimmune encephalomyelitis is an animal manifestation of human multiple sclerosis, an autoimmune disease in which the immune system mistakenly attacks its own organism, causing damage to the brain as well as to the nerves of the spinal cord.