If you appreciate food at all (And, let’s face it, if you’re reading a blog about fruit, you probably do!) you definitely have that one friend – the one obsessed with chilis who’s always daring their tongue, and their own best judgement, to go hotter and hotter.
As it turns out, their acts of heroics may be less voluntary than you think. Because scientists are finding out that what makes chilis anything but chilly is some pretty powerful stuff.
But before we dig into the details, it might be helpful to understand why peppers are hot at all.
Chili peppers get their extra special kick from a compound called capsaicin, which is part of a broader group of chemicals called capsaicinoids. (Though it’s not all fire and brimstone. Capsaicinoids are actually derived from the same compound that gives vanilla its lovely—and notably mild!—smell and taste.)
The way capsaicin interacts with our bodies is actually pretty unique. The compound specifically works with a particular protein that acts as a sensor on the tips of our nerve cells. Called TRPV1, the protein is typically responsible for letting the brain know when we’re facing pretty extreme heat levels. (Think, 109 degrees Fahrenheit and higher.)
Once capsaicin enters the picture, it “turns” this protein sensor on, sending a message to the brain that there’s some serious heat in play. So technically, when you’re eating a chili pepper, you’re not actually tasting it at all—you’re feeling it.
It’s one of the reasons why our bodies react so differently—and even extremely—to the substance, and the definitive reason why “heat” isn’t on the list of official flavors detected by the tongue, which otherwise includes sweetness, bitterness, saltiness, sourness, and umami, the earthy type of taste you get out of mushrooms.
And since TRPV1 is found all throughout the body, it’s why we can feel a chili pepper’s burn lingering on our skin if we come in contact with the natural heat packers.
But how can something that literally makes our bodies feel like mini fires are happening on our tongues be found so enjoyable by so many people?
That’s, again, thanks to the exquisite artwork that is the human body.
Our nerves aren’t just wired to our brains to let the big, grey machines in our heads know what’s going on. The whole point of the brain receiving messages from the body is for the brain to do something about it.
And when it comes to experiencing insanely hot temperatures, our minds are there to comfort us.
Aside from interacting with TRPV1, capsaicin triggers our bodies to produce something called substance P. And, yes, that’s “p” for pain. The chemical compound is responsible for sending word through our neurotransmitters that our body is experiencing it and that the brain should send help.
For the kind of heat sensation triggered by chili peppers, that aid comes in the form of endorphins. You might better recognize these chemicals for the work they do to “reward” us after a workout.
Technically, endorphins work by blocking nerve cells from transmitting signals that make us feel pain. But the instant relief can almost feel like a small sense of euphoria for many people.
On top of this, the brain will also send small amounts of dopamine to combat substance P. And you might better recognize this chemical for its role in making you feel good after doing something pleasurable like listening to music, sitting in the sun, meditating or—once again—exercising.
Indeed, endorphins and dopamine are the culprits behind the notorious “runner’s high” that comes after or in the middle of an otherwise exhausting jog.
But when it comes to chili peppers, the chemical feel-good recipe is getting us high on heat – and sends many into a sprint to get more, more, more of the stuff.