Munch a bit of habanero pepper or hot-sauce-soaked jambalaya, and you’ll notice a tingling numbness in your mouth followed by a burning sensation. If that burning sensation is sufficiently strong, your nose and eyes will start to run, and your mouth and throat will start to generate mucus.
You may not be able to feel it, but your stomach and parts of your intestine will also start secreting excess fluid, says Dr. Brett Comer, a surgeon and ear, nose, and throat specialist at the University of Kentucky College of Medicine. Why does all this happen? Like spraying water on a filthy car, your body turns on the waterworks in order to wash away the offensive spice. “When your mouth or throat encounters any foreign object that’s noxious, the thinking is that liquid helps to move that out,” Comer explains. Some people even develop diarrhea or an upset stomach as a result of the extra mucus released into the gastrointestinal tract in response to spicy food, he adds.
As every hot-sauce aficionado knows, a plant compound called capsaicin deserves credit for the snot-unleashing heat of spicy chili peppers. One study on the physiological and therapeutic effects of capsaicin found that the compound causes its unique brand of “excitation” by locking onto a specific type of pain receptor. “This excitation leads to the feeling of heat or burning pain, blood vessel dilatation, reddening of the skin and body temperature elevation,” says Anthony Dickenson, author of the study and a professor of neuropharmacology at University College London.
Capsaicin can trigger these effects whether it’s eaten or applied to the skin in the form of a topical cream, Dickenson says, which is why some arthritis and muscle-pain creams contain capsaicin. Once that initial “excitation” has died down, the affected pain receptors tend to become desensitized, he says, which can decrease pain locally. “There is also a high-dose [capsaicin] patch that makes the pain-sensing nerve endings pull back from the application site—sort of escaping the insult—and this can lead to several weeks of pain relief,” he says.
Apart from its ability to combat pain, capsaicin has demonstrated several other potential health benefits. Research from China has linked the consumption of capsaicin-containing spicy foods to lower mortality rates. While explanations for this link are shaky, some researchers say that capsaicin seems to bolster heart and metabolic function. Other experts have also found evidence that capsaicin can trigger a healthy form of cell death that may slow or prevent the kinds of mutations that lead to cancer.
There’s also evidence that capsaicin can protect your heart and waistline. Eating capsaicin has anti-obesity effects, according to a 2017 review. And a 2015 study found that eating capsaicin may counteract the accumulation of visceral fat—a type that builds up in your gut and around your organs, and that is linked to a number of diseases. Another small study of 36 adults found that adding capsaicin to their diets for four weeks improved some measure of heart and arterial function, probably by increasing healthy blood vessel dilation.
It’s not clear whether taking capsaicin in a supplement can offer the same benefits as adding fresh capsaicin-containing peppers to your diet. And some researchers have found evidence that using topical creams that contain capsaicin long term could raise a person’s risk for skin cancer—especially before they spend time out in the sun.
But apart from those caveats, most of the research suggests that adding spicy foods to your diet is associated with a range of health perks.
The real head-scratcher, though, is why so many people seem to enjoy the pain and burning associated with eating spicy food. There are theories—including the appeal of thrill seeking activities. “People seem to enjoy pushing the limits of what we can take,” says Paul Rozin, a professor of psychology at the University of Pennsylvania.
Rozin points out that humans enjoy riding roller coasters, watching scary movies and engaging in other forms of “benign masochism.” And when it comes to hot peppers, “we’ve found that the preferred level of burn is just below the level you can bear,” he says. Basically, people seem to like pushing themselves to the limit.
Some experts have hypothesized that this sort of behavior may help prepare us for real-world challenges. But Rozin says that the joy of eating hot peppers may stem from a more straight-forward benefit. The ability to tolerate—and even relish—a bit of capsaicin-induced pain allows people to incorporate healthy sources of nutrients into their diets that would otherwise seem inedible, he says.
So bring on the hot sauce—assuming you can take the heat.