Why You Should Skip the Brain if You Eat Your Friends

Cannibalism is mostly the stuff of gory, post-apocalyptic science fiction—a staple of shows like The Walking Dead and The Santa Clarita Diet and movies like Mad Max and The Bad Batch, out this weekend (and which VICE produced). But obviously, it's not something any of us ever have to worry about encountering in real life—and unless you're a sociopath, you can probably agree that's a very good thing.

James Cole, an archeologist and lecturer at the University of Brighton in England, puts it a little more elegantly: "We're at a point today where our Western cultural influence is quite widespread, and within our cultural practice this is something that's not deemed suitable to do," he says. "That's a relief, frankly."

And yet, especially for those of us who are still plodding along with Rick and the gang in season 7, it's hard not to at least consider a fleeting thought: What would happen if we actually had to rely on the dearly departed for sustenance?

After all, populations in the Homo genus ate their own kind in one way or another for at least a million years, Cole says. Fossils dating back 800,000 years, in fact, show evidence of cannibalism by our Homo ancestors. The Fore people in Papua New Guinea ate parts of the dead until at least 1960.

Still, that's not to say we ran around killing and eating people as a regular part of our diet. For one thing, that wouldn't have been an efficient way to feed a group of 25, the ideal size for a nomadic group of hunter-gatherers in the Paleolithic era, Cole explains.

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In a paper published in Scientific Reports this year, Cole analyzed and recorded the calorie content in an average adult male and compared the data to other fauna. The skeletal muscle in a man's body contains 32,376 calories, enough to feed a nomadic tribe of 25 for just half a day. In other words, the human body was a mere appetizer compared to other options on the menu at the time—like, say, the mammoth: At 3.6 million calories, its carcass could feed the same group for up to two months.

"When you compare us to the deer or the mammoth or the woolly rhino, we're actually a really small animal," Cole says. "I can't think of any nutritional benefit."

So why'd we do it? Researchers like Cole think there could have been a social benefit to the practice: Some cultures may have honored the dead by eating a mouthful of their flesh to carry their soul forward—a key to maintaining social cohesion. Funerary acts like these were common in the Wari' tribe of the Brazilian Amazon until around the mid-20th century, when Christian missionaries briefly converted them.

Researchers also found 14,700-year-old human remains in Gough's Cave in the United Kingdom that showed signs of ritual cannibalism, according to a 2015 study published in the Journal of Human Evolution. Among other things, they discovered "chew marks left by human bites," cut marks from stone tools used to skin and fillet human remains, and skulls that had been modified into skull-cups, says Silvia Bello, a researcher in the earth sciences department at the Natural History Museum in London and lead author of the study.

Body parts weren't just used as drinking vessels, either—they were also considered to be a form of medicine. "People would grind up bones and take them for things like rheumatism. Epileptics would line up at executions to collect blood to treat their seizures," says Bill Schutt, author of Cannibalism: A Perfectly Natural History. (Schutt adds that he once ate a woman's placenta for research—the woman's husband, a chef, prepared it osso bucco style. Schutt paired his serving with an Italian red wine.)

If picturing that scene grosses you out, it's partly because your knee-jerk reaction to cannibalism has been shaped by Western culture and the social values you place on the people around you. But if you were to actually take a bite out of another human today, the odds are that your body probably wouldn't detect anything outside of the ordinary.

"Our digestive tracts would not have to undergo any types of adaptation or evolution to be able to cope with eating humans," Schutt says. For the most part, there's nothing inherently dangerous about human meat. If anything, our flesh is comparable to that of a pig—both species are omnivores and eat similar diets, Cole says.

That said, not all body parts—or bodies—are created equal. Eating human brains, for instance, can cause a neurodegenerative condition called kuru, which has been compared to mad cow disease. People with kuru experience an increasing loss of bodily control—they have trouble walking, speaking, and eventually, swallowing. An outbreak of kuru is believed to have killed roughly 1,000 Fore people in the late 1950s. "If you consume the brains or the flesh of someone who's got kuru, it's one hundred percent lethal," Schutt says.

Obviously, it would also be inadvisable to eat someone with a blood-borne disorder like hepatitis or HIV. At least, you wouldn't want to order them rare: "You'd effectively introduce [the diseases] into your own system the same way you [would] through the exchange of bodily fluids," Cole says. Otherwise? There's probably very little your digestive tract—or your immune system—would object to.

"At the end of the day," Cole says, "we're just flesh and fat and protein, just like any other animal."

The Bad Batch hits theaters this Friday, June 23.

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