Fact or Fiction: Is the Cordyceps Fungus in “The Last of Us” Real?

In the first scene of the hit television series, The Last of Us on HBO, a scientist in the 1960s explains to a talk show host why a parasitic fungus could cause a future pandemic. 

In the next scene, almost forty years later, hundreds of human zombies run around a city with fruiting bodies of the Cordyceps fungus growing from their throats and bodies, attacking other humans to spread the disease. 

It’s pretty effective entertainment. But could it happen?

The short answer is maybe … but definitely not for a million or more years. 

In this article, we take a look at fact versus fiction and why Cordyceps sinensis, a parasitic fungus related to mushrooms that has been highly valued in traditional Chinese medicine for over 1,300 years, is an asset, not a threat, to humans.

FICTION: Cordyceps can turn humans into zombies

Cordyceps cannot take over a human’s body. But its actions in nature did provide the inspiration for the zombies in the video game and television series, The Last of Us. 

According to Neil Druckman, the creative director of The Last of Us, he and the director, Bruce Straley, were watching an episode of BBC’s Planet Earth that described how one of 400 known species of the fungus Cordyceps, Ophiocordyceps unilateralis, infected and took over the bodies of ants.REF#632 The show described the infected insects as “zombie ants,” which gave the creators a perfect visual for how their human zombies would look and be controlled.

Of course, the film and the game that inspired it are fiction. Since the early 1930s, when the first zombie film, “White Zombie,” was released, zombies have entertained generations of moviegoers. After the film, “Night of the Living Dead,” came out in 1969, zombies became defined as walking corpses who proliferate by infecting others. 

While plot lines change, all zombies share a similar characteristic: They have been altered in such a way that they lack free will. Becoming a zombie is a fate worse than death — and the fear of that fate provides the ultimate scare tactic in modern horror films.

João Araújo, the Assistant Curator of Mycology, Institute of Systematic Botany at Penn State University, and an expert in insect-related fungi, has studied ant-attacking fungi for over ten years. He has found that each species of cordyceps has evolved over long periods to match only one specific species of insect.REF#633

When asked by National Geographic magazine whether we should fear Ophiocordyceps unilateralis, Araújo responded that it would take over a million years of additional evolution for the fungus to mutate genetically in a way that could threaten human beings.REF#634 He didn’t believe that was likely to happen.

FACT: Fungi Were One of the Original Complex Life Forms on Land

There are over 120,000 known species of fungus, including yeasts, mildews, molds, rusts, smuts, and mushrooms. The genus has survived over a billion years of evolution, assisting in the growth and survival of plants and animals without threatening humans. 

Fungi break down dead organic matter, from rocks to plants to insects, and release carbon, oxygen, nitrogen, and phosphorus into the soil and the atmosphere. Without fungi, the earth would be covered in millions of years of plant debris that never decomposed.

FACT: Fungus Can Be Both Good and Bad

All fungi are heterotrophic, meaning they get their food from outside sources, either from dead organic matter or living things.REF#632

Fungi that break down dead organic matter (saprotrophic fungi) are beneficial when they enrich our soil but damaging when they cause dry rot in buildings or rust metal structures. 

Symbiotic fungi get their energy from living things, including plants, insects, and animals, in order to live and reproduce. They can either support or destroy their hosts. 

Some symbiotic fungi aid in the production of food items like bread, chocolate, pickles, salami, and beer. Some, such as mushrooms, morels, and truffles are edible delicacies. Others, like the mold penicillium, are used to help ripen cheese and produce antibiotics, including penicillin.REF#635

Then, there are the necrotrophic fungi. These parasitic fungi are both symbiotic and saprotrophic, infecting their hosts and then breaking down their dead bodies over time. 

Ophiocordyceps is a genus of necrotrophic fungi with 140 known species that grow on insects. 

Ophiocordyceps unilateralis, a particularly fascinating necrotrophic fungi, is the species that inspired The Last of Us. It attaches to specific species of ants and hijacks their brains and bodies to make it easier for the fungus to release spores and reproduce. 

Scientists believe this fungus uses mind control to force the ants to leave their nests, climb into trees, and attach to leaves. Once in the tree, the fungus digests the nutrients it needs from the ant and grows grass-like stalks out of the ant’s dead body, which it uses to disperse spores across the ground below, infecting other ants in the area. 

FACT: Ophiocordyceps Benefits Human Health

There is another necrotrophic species of the fungus Ophiocordyceps that grows wild in the Himalayan foothills of Tibet and Bhutan at an altitude between 9,800 and 16,400 feet. In the wild, Ophiocordyceps sinensis infects just one insect — the ghost moth — in its caterpillar stage. 

The fungus kills the caterpillar while it is living underground and uses its body for nourishment and growth. After devouring the caterpillar from the inside, it reproduces by sending fruiting stalks (grass-shaped mushrooms) from its head, which emerge from the soil and release spores in the air to infiltrate other ghost moth caterpillars. 

While disastrous to the ghost moth, Cordyceps sinensis has been harvested in Asia for centuries for its beneficial medicinal properties. Because it is rare and hard to find and cultivate, this fungus is extremely expensive and rarely sold outside China.

Herbalists, therefore, worked to develop a species called Cordyceps militaris using barley as its substrate for cultivation. 

Research shows that the fruiting bodies (stalks that grow out of the substrate) of Cordyceps militaris have similar benefits to the fungal species that uses ghost moth caterpillars as its host. Because the fruiting bodies grow from a plant not an insect, they are vegan. The list of cordyceps benefits is significant:

• Provides antioxidant support 
• Promotes male reproductive health
• Supports your immune system
• Smooths out the body’s stress response cycle
• Helps maintain healthy energy levels
• Supports physical stamina

FACT: The Market for Cordyceps Supplements is Growing

The more we learn about the benefits of specific fungi and mushrooms, the more demand there is for supplements that contain them. Because of its health benefits, Cordyceps supplementation was expected to have a compound annual growth rate (CAGR) of 10.4 percent between 2018 and 2026, with supplements sold in capsule or powder form.REF#636 Gaia Herbs offers Cordyceps Mushrooms in vegan capsules with a suggested dosage of one per day. Cordyceps can also be taken as part of a blend of mushrooms from Gaia Herbs that supports specific health issues, including:

• Immune support 
• Respiratory health
• Adrenal health
• Mental clarity
• Support for energy levels and stress

When purchasing Cordyceps, make sure the fruiting bodies were grown in conditions similar to their natural habitats and harvested from their growing substrate. Look for brands that state they do not incorporate any of the growing medium into the final product. Additionally, make sure they are 100% Cordyceps and nothing else—no fillers, starch, or grains.

You can rest assured that rather than being a danger, Cordyceps has the potential to improve your energy and stamina and help you maintain great health for years to come.* 

Instead of imagining disaster around the corner, enjoy the rest of The Last of Us television series! It’s been getting great reviews.