Could a Zombie Survive On a Diet of Human Brains?

Most people have thought about what they would do in the event of a zombie apocalypse. You know where you’d hide, what you’d weaponize, and the destination you'd attempt to reach. But few of us have ever thought about the scenario from the perspective of the zombies. Leaving aside the grossness and tragedy of their head-chomping lifestyle, is a brain-heavy diet providing them with everything they need, nutrition-wise?

Food for Thought

Thanks to pop culture, many people associate brains-as-food with zombies, or with movies like Indiana Jones and the Temple of Doom, which presents a monkey brain as the grossest thing imaginable. But brains used to be on the menu for the non-undead a lot more than they are today.

Most cultures have some version of brain dishes, from tacos de sesos to brain’n’eggs to Ohio River Valley fried brain sandwiches. The beloved cookbook The Joy Of Cooking used to feature baked brains, boiled brains, and sauteed brains (not monkey ones, admittedly, or served chilled as a dessert straight out of a disembodied monkey head).

While you can still find brains for dinner here and there, featured as upmarket offal in "nose-to-tail" restaurants or showing up as less-upmarket fare canned in milk, it’s a vastly less popular food than it once was. In part this comes down to people having more choice and not everyone necessarily wanting to chow down on a chunk of goop that once housed a cow’s thoughts, but there are health reasons as well.

The emergence of variant Creutzfeldt-Jakob disease (vCJD) in the 1990s didn't do the brains-as-food industry any good. Like "mad cow" disease (a.k.a. bovine spongiform encephalopathy, or BSE), vCJD is a prion disease, which is caused by transmissible proteins in the brain misfolding and causing other proteins near them to follow suit. Today, there are much stricter laws surrounding the storage and distribution of brains for consumption than there used to be.

Prion diseases are both very rare and very serious—there are only about 300 cases per year in the U.S.—but they lead to neurodegeneration and death. The Fore people of Papua New Guinea, for example, have a tradition involving cooking and eating the brain of a deceased loved one as a way of freeing their spirit. However, in the 1950s, this led to an outbreak of the fatal prion disease kuru, a neurodegenerative disorder characterized by tremors and uncontrollable laughing fits that ends in death.

While a lot of infectious or potentially infectious material can be destroyed by thorough cooking, prions cannot. The only way the Fore got the disease under control was to give up cannibalism.

Would zombies be willing to give up eating brains? It’s hard to say. The idea of the walking dead feasting on gray matter is a newer trope than many people realize. George A. Romero’s zombie films, which cemented most of the traits of zombies as we know them—shambling, mindless, groaning killing machines with fleshy bits falling off them—feature them eating human flesh in general, with no specific parts preferred. It wasn’t until 1985’s unrelated Return Of The Living Dead that the concept of zombies snacking on brains was codified, with one zombie specifically explaining that eating brains "takes away the pain of being dead."

The Problem With Brains

There's another issue with brains: They're high in fat. This largely comes down to myelin, the coating on axons—those fibers that connect different parts of the brain—which functions in a way not dissimilar to the plastic insulation on a wire. Brains are also very high in cholesterol; Fitbit claims that 1 pound of lamb’s brain contains 20 times your daily recommended cholesterol intake.

Those numbers go way up for a human brain. "An adult human brain weighs about 3 pounds. It would also be somewhat fatty," Monroe Turner, Ph.D., a computational neuroscientist at the University of Texas at Dallas’s Center for BrainHealth, tells Mental Floss. "The regions of the brain have different characteristics: gray matter is high in protein, for instance. In white matter, the fiber tracks that connect the brain cells are fatty, and since there are more neurons to connect in human brains than in animal brains, it would be a fattier meal than an animal brain. And cerebro-spinal fluid (CSF) might be salty."

But brains do contain quite a lot of vitamins and nutrients. There’s vitamin C in there, plus B12, iron, and niacin. "While eating a human brain wouldn’t help your own brain, it might contribute to a balanced diet," Turner says. "To actually help your brain, you should exercise it by applying cognitive strategies to your daily life."

A brain is an incredible thing. You can see why zombies dig ‘em so much.

The Verdict

Which brings us back to the question of the nutritional value of eating brains. The bottom line is, it's not really possible for a zombie to maintain a healthy lifestyle—well, as healthy a lifestyle as an undead human can have—by munching mostly on human brains. The high cholesterol will do them no favors long-term, and dehydration will likely be an issue given the salt content of cerebrospinal fluid and blood. All of which really gives you something to think about while they're tearing you apart.