A new study shows that cannibalistic islanders developed resistance to neurological diseases caused by prions.
The Fore people of Papa New Guinea have a long and fascinating history but they are often known for only one thing: cannibalism. Well into the 20th century, these island natives would perform funeral rituals that involved eating the deceased – including their brain.
Yet, in the early 1900s, members of the tribe began to experience body tremors and uncontrolled bursts of laughter. This laughing sickness, known as kuru on the island, was in fact a degenerative neurological disease. There is no cure. Some two percent of the population would succumb to this each year. By the 1950s, the greatly reduced Fore people outlawed cannibalistic funeral rites.
Some Fore people survived the epidemic. When researchers began to examine how some people could eat human brains to their hearts content while others went mad, they discovered an interesting genetic mutation in the survivors. V127 provided protection against infectious prions – the proteins that fold abnormally on the brain, creating lesions or holes. Survivors with two copies of the mutation (one from the mother, one from the father) were twice as capable of resisting neurological disorders caused by prions such as mad cow disease, Creutzfeldt-Jakob disease, even dementia.
Researches crafted mice with the V127 genetic mutation. “From the human genetic work the Unit has carried out in Papua New Guinea we were expecting the mice to show some resistance to disease,” said Dr. Emmanuel Asante, a lead researcher in the study. “However, we were surprised that the mice were completely protected from all human prion strains. The result could not have been clearer or more dramatic.”
Although kuru greatly reduced the population of the Fore people, a new study suggests that had the remaining islanders continued their traditional practices, a stronger, prion resistance population would have repopulated the island.
“This is a striking example of Darwinian evolution in humans,” said Dr. John Collinge, the senior author of the study and a professor of neurodegenerative disease at University College London, “The epidemic of prion disease selecting a single genetic change that provided complete protection against an invariably fatal dementia.”
The scientists hope the revelations found in the Fore people will help find the root cause of dementia. With luck, their work may even give insights into finding a cure.
