Scientists tackle a curious food mystery — why so many people hate cheese

For all of the cultural and internet love that cheese inspires, cheese haters still walk among us. These are people who don’t just dislike the beloved treat — they are thoroughly disgusted by it. And they are everywhere.

While, obviously, not all people hate cheese — a single French citizen ate about 25.9 kilograms of cheese per year in 2013 — the number of people who dislike cheese was high enough to surprise Jean-Pierre Royet, a neuroscientist and the author of what appears to be the first and only scientific study on the brains of cheese-haters. In his 2016 study "The Neural Bases of Disgust for Cheese: An fMRI Study," he found as many as 6 percent of 332 people disliked cheese so much that they were disgusted by it.

The study tackles some big ideas in the world of cheese hatred. Part of the hatred, the study suggests, comes down to negative experiences with cheese, like the misery of lactose intolerance (18 percent of subjects said they had milk intolerance).

However, some people find it purely disgusting, even without prior negative experiences.

“This food is perceived as being particularly disgusting by a lot of people," Royet tells Inverse.

Ultimately, the study found that a key brain area associated with reward, the ventral palladium, is deactivated in cheese haters. Instead, disgust is triggered.

That may seem impossible to a lover of cheese, but it's actually a fairly normal reaction, explains Paul Rozin, a professor emeritus at the University of Pennsylvania and a cultural psychologist who studies food and human life.

“The great majority of the world thinks that cheese is disgusting,” Rozin tells Inverse.

The science of hating cheese — The reasons people give for thinking cheese is gross actually make a lot of sense.

Cheese-making begins with curdling milk, the first step towards spoilage that smells abhorrent if you encounter it by accident. This is a classic smell of decay, Rozin says. On its own, it is enough to turn your stomach.

“The classic stimulus for disgust is the decay odor, which is what cheese has,” Rozin explains.

Cheese, in turn, never stops emitting that decay odor. However, the way we feel about that odor can change.

“The smell of the cheese, for some people, becomes pleasant, even though it's a signal of decay,” Rozin says.

This learning process fascinates Rozin more so than the simple hatred of cheese. It's an understudied process, but there are few ideas as to why it's possible.

The theoretical origin of cheese hating – Royet, the neuroscientist, found some people learn to hate cheese because of negative experiences through his study. Cheese fans, meanwhile, have to learn to love that decay odor.

Rozin explains why: When children are as young as two years old, they’ll basically eat anything. In the 1980s, he did a study on children between 2 and 5-years-old. The infants were presented with 30 normal adult foods like spinach, Kraft cheese, chips, or candy bars, as well as inedibles like crayons, or “doggie doo” – a mixture of peanut butter, Limburger cheese, and blue cheese extract.

In most interactions with substances, the kids “accepted” the item, which means they appeared to be about to eat or drink it about half of the time. And the youngest kids, below the age of 2.5, had far fewer qualms with objects like crayons or doggie doo.

However, between the ages of 16 months and 5 years, Rozin and his team observed a clear developmental trajectory towards thinking certain things are disgusting. More recently, other studies suggest by the age of 3 or 4-years-old, kids develop disgust.

It’s at this point, Rozin says, we learn not to eat “stinky things" — and it's natural to be off-put by particularly pungent “decay” odors. In short, we have the capacity to become cheese haters.

But that emergent anti-decay attitude may not last long. In previous work, he has proposed that a “disgust reversal” occurs. In this situation, context clues and certain amounts of social conditioning prompt people to re-evaluate things that may give off an odor of decay, cheese included.

“‘[Young children] would have eaten stinky cheese. Then, they don't. They think of it like poop and then they reverse and love it again," Rozin says.

Why this reversal of taste happens is extremely unclear, he explains, and it doesn't happen for everyone. For those who experience it, he thinks there could be two explanations.

How we learn to love cheese again – Most humans come hardwired with an innate love of sweetness and distaste for bitter substances. Everything else has to be learned through either experience or context.

Assuming you don’t have lactose intolerance or other adverse reaction to cheese that might color than context, social conditioning can play a role in whether or not we see certain foods as acceptable.

Within the context of many European countries and the United States, cheese isn’t typically regarded with disgust. In turn, there’s pressure to get over the smell of it as a child.

“Part of it is exposure,” Rozin explains. “The people they admire, like adults and their oldest siblings, they love it. There's a social pressure to like it.”

"There's a social pressure to like it [cheese]."

In his research on spicy food, Rozin also put forth a theory called benign masochism, which suggests we tend to like powerful negative experiences that don’t threaten our lives but fall just short of being truly painful (emotionally or physically).

He likens it to watching a tear-jerker movie, or eating just enough spicy food to make you uncomfortable but not desperate for relief.

“We come to enjoy the very fact that our body thinks: ‘this is bad,'” Rozin explains.

Cheese may be pungent enough to provide some of that thrill, but it certainly doesn’t torture us the same way that spicy food or scary movies can. Still, it could be one reason people tend to go for particularly odorous cheeses that may turn others off.

The biggest unanswered question in the complicated field of cheese-hater research isn’t why people love cheese: It’s why some people still hate it when people who share their culture mostly love it.

There's still a higher-than-expected percentage of French people, by Royet’s estimate, that don’t like cheese. Social conditioning and benign masochism are clearly not the only processes at work.

This, says Rozin, is a foundational question in the area of food-related research. And the reason that cheese haters persist in a culture where cheese is normal, will require additional study.

“These are all complicated issues," he says. "And there's a lot of research to do, as you can tell from talking to me."

In the meantime, this means more cheese for the rest of us.