Eating the brain of another human being can cause kuru, a disease of the nervous system. Kuru occurs because our brains contain prions that transmit the disease. The symptoms include arm and leg pain, coordination problems that become severe, difficulty walking, headache, swallowing difficulty, and tremors and muscle jerks. The average incubation period of this disease is 10 to 13 years but some cases have had an incubation period of 50 or more years. Most die 6 to 12 months after the first appearance of symptoms. This disease was discovered when researchers went to the highlands of Papua New Guinea in the 1930's/1950's. They found a tribe that had an estimate of eleven thousand people called the Fore, around 200 people dying a year from an inexplicable illness.
