Cannibalism may be responsible for a genetic mutation of human prion proteins that makes the individual completely immune to “mad cow” disease, and could provide scientists with new ways of treating other incurable brain diseases.

Scientists discovered this particular mutation while studying the Fore people of Papua New Guinea, who have had a long history of cannibalism formed out of a sign of respect by consuming the dead. Because of their custom (prohibited in the 1950s), kuru was a common brain disease that afflicted the Fore people that had nearly devastated the entire population until recently. Since then,

Funded by the Medical Research Council, scientists studied the prion gene sequence of Fore individuals who have survived in hopes of discovering a way of conferring long-term resistance against kuru, and other brain diseases such as Creutzfeldt-Jakob disease (CJD), bovine spongiform encephalopathy (BSE). Using the genetic work the scientists produced, the MRC Prion Unit of the Institute of Neurology at University College London had made a change in the 253 building blocks that make up prior proteins on laboratory mice.

Rather than finding the mice with increased resistance against these brain diseases, scientists found that the furry human substitutes were entirely resistant to all human prion strains. It should be noted that in the study, the scientists point out that while resistant, the mice could be infected with variations of CJD that the Fore had not been exposed to, which further strengthens the idea of evolutionary mutation.

Prion diseases affect the nervous system and can cause dementia, loss of coordinating movements, and eventually worsening with time, death. This discovery could lead to significant steps towards treating devastating diseases including Alzheimer’s, which is responsible for most of the dementia that inflicts one in 14 adults over 65.

The original research is currently published in Nature.