Turns out cannibalism may be good for your brain

The human body is as strange as it is fascinating. The way our bodies have evolved over the millennia to adapt to our environments and habits is simply mind boggling. What’s most interesting is the fact that, in many cases, it didn’t even take millennia for humans to evolve, or even centuries for that matter. A perfect example would be the Fore people, a small tribe in Papua New Guinea that, until the late 1950s, had an odd funeral ritual which involved tribe members consuming the brain of the deceased.

For those of you who aren’t aware, consuming human flesh is more than just reprehensible, it’s very dangerous. This became apparent to the Fore people when, beginning in the early 20^th century, members of the tribe began to develop a neurological disorder known as kuru. The disorder is caused by infectious prions, which are essentially just abnormally folded proteins that form lesions in the brain and can prove to be very fatal. With somewhere around 2% of their tribe dying every year, the Fore people were forced to abandon their cannibalistic funeral ritual in order to prevent further cases.

Although the disorder can take a while to develop, and therefore cases of kuru began popping for a few decades after the tribe no longer practiced the ritual, the number of tribe members suffering from the disorder has since decreased drastically. However, this may be due to more than just the cessation of the funeral ritual, as researchers have discovered a mutation in some of the tribe members known as V127.

This genetic mutation was found in members of the Fore tribe who had survived the kuru epidemic, while those who developed kuru didn’t have the mutation. Suspecting that there was potential link between V127 and the decrease in kuru, the researchers decided to genetically engineer mice to have the mutation and then injected them with infectious prions. What they found was that mice with a single copy of the mutation were resistant to kuru, as well as a similar neurological disorder. Mice equipped with two copies of V127 were resistant to even more disorders, including variant Creutzfeldt-Jakob disease, which is more or less a human form of mad cow disease.

“This is a striking example of Darwinian evolution in humans, the epidemic of prion disease selecting a single genetic change that provided complete protection against an invariably fatal dementia,” said Dr. John Collinge, the senior author of the study and a professor of neurodegenerative disease at University College London, in a statement.

According to the researchers, had the tribe not ended its cannibalistic funeral ritual and spread of kuru wasn’t stopped, the V127 mutation would have likely made its way across the region to create an entire population of people that would be resistant to kuru and other neurological disorders. The researchers also claim that further study of V127 could lead to some new insights into the prevention of prion disease.