From The Washington Post: How a history of eating human brains protected this tribe from brain disease.

The sickness spread at funerals.

The Fore people, a once-isolated tribe in eastern Papua New Guinea, had a long-standing tradition of mortuary feasts — eating the dead from their own community at funerals. Men consumed the flesh of their deceased relatives, while women and children ate the brain. It was an expression of respect for the lost loved ones, but the practice wreaked havoc on the communities they left behind. That’s because a deadly molecule that lives in brains was spreading to the women who ate them, causing a horrible degenerative illness called “kuru” that at one point killed 2 percent of the population each year.

The practice was outlawed in the 1950s, and the kuru epidemic began to recede. But in its wake it left a curious and irreversible mark on the Fore, one that has implications far beyond Papua New Guinea: After years of eating brains, some Fore have developed a genetic resistance to the molecule that causes several fatal brain diseases, including kuru, mad cow disease and some cases of dementia.