We've all lived through it: Thinking you can take the heat of a spicy dish and then realizing, to your horror and your friends' amusement, that your mouth has become a fiery hell that, like hiccups, seems never-ending but really only lasts a few minutes.
Why Do Spicy Foods Taste Hot?
As pretty much everyone knows by now, the "hot" in hot foods comes from capsaicinoids, a nonnutritive chemical compound that our brains interpret as heat or, in excessive quantities, even pain. Critically, we don't "taste" capsaicinoids with our tastebuds, the receptors on our tongue and in our mouths that light up when they sense one or more of the five basic tastes—sweet, sour, salty, bitter and umami. Instead, spiciness raises the alarm directly in the nerve endings that are pretty much everywhere on our bodies to a greater or lesser degree, not just our tongues. It's part of what's called the common chemical sense.
"If you put some sugar on your skin, you're not going to feel sweet, but rather than having specialized receptors or cells, spiciness triggers receptors that are common in the body on the end of sensory nerve endings," says Danielle Reed, associate director of the Monell Chemical Senses Center in Philadelphia and a noted researcher in the science of taste who's currently conducting a study to see if sensitivity to capsaicin could be genetic. "So if you put a chile pepper on your eye—and you should not do that—you'll get a burning feeling."
That also explains why, even long after what your nerves interpret as heat subsides in your mouth, you're likely to revisit that "heat" from a particularly spicy meal at, er, the other end. "Mucous membranes in particular—not to be indelicate, but they do call it 'the burn that bites twice'—have much more accessible sensory nerve fibers," Reed says.
Our reaction to capsaicin is a clue to why spiciness exists at all. Birds, unlike us mammals, don't sense capsaicin as heat, so a leading theory is that plants evolved so that birds could still eat the fruit (the chile pepper) of the plant and propagate its seeds while dissuading mammals from eating and damaging the plant itself. The way spiciness works in humans also provides a disturbing hint at the havoc COVID-19 may be wreaking on our physiology. It's well-known that one of COVID's telltale symptoms is loss of smell and taste, but many sufferers have also completely lost their ability to sense the heat from capsaicinoids—meaning the virus may be fundamentally altering our nerve endings.
So if our nerve endings are basically telling us to avoid capsaicin, why, exactly, have human beings been eating chile peppers for nearly 10,000 years? "Humans are perverse," food-science author Harold McGee says. "So we can sometimes take pleasure in pain—a rollercoaster ride is an example of something that's scary but safe. We can enjoy a basically unpleasant sensation for its own sake, and bodies can respond to it by emitting chemicals that alleviate the unpleasant sensation so you can feel good afterward."
Getty Images / Nickilford / Jonathan Knowles / Antonio_Diaz
How Do You Stop the Burning from Spicy Food?
We'll just give you the bad news up front: There's no magic potion that's going to be able to put out that five-alarm fire raging between your tonsils.
"The basic problem is that by the time we feel the pain, the compounds have already gotten inside ourselves, so the idea you can immediately rinse them away just doesn't work out in practice," McGee says.
Don't believe him? Unfortunately, taste scientist Reed agrees. "I know there are a lot of home remedies, but I don't know of any scientific principle that'll let you out," she says.
Milk & Other Dairy Products
The most commonly espoused home remedy is consuming dairy products, as they contain proteins called caseins that bind neatly with capsaicinoids, preventing any capsaicin that hasn't already hooked onto a receptor from latching on, safely washing the now-neutralized compounds down your gullet instead. Many foodies have suggested that whole milk is better than skim milk for this purpose.
"In practice, you can rinse out the reinforcements that would prolong the sensation, [though] you're not going to alleviate what you're already feeling," McGee says. "Fatty materials, milk included, will tend to pick up stray molecules in our mouths."
Bread, Honey and Other Distractions
Many of the other frequently heard antidotes for spicy foods are essentially just distractions, including bread or honey. "A possibility is that bread is a solid, so you're chewing on it and generating all sorts of other touch sensations distracting you from the pain," McGee says. "Like what's going on with bread, sweetness is a distraction, and so your brain is apportioning the attention it can pay to things."
For the most immediate relief from spicy heat, McGee suggested literally cooling things down—even if the "heat" you feel from a chile isn't really related to temperature. "The temperature effect is probably the quickest way you can deal with the problem," he says. "Get an ice cube out of your drink and suck on it."
How Do You Make Spicy Foods Less Spicy Before You Eat Them?
It should go without saying that if you want your food to be mild, then go easy on the chiles. But we've all made mistakes, like misjudging a recipe or forgetting that, when it comes to chile peppers, it's the smaller, younger ones that are spicier than the bigger, older ones.
As with stopping the burning in your mouth after you've eaten spicy, there are a lot of widely accepted but scientifically unproven techniques for toning down a spicy dish, like adding honey. But the only guaranteed method is to dilute it, meaning you may need to double (or more) every ingredient in your recipe except the chiles.
Another approach is to have something on hand to coat your mouth so you can prevent capsaicin from hitting those nerve endings at all. "Especially something like sour cream, which is fatty, will absorb that stuff and coat your tongue to make it difficult," McGee says.
But if you're hellbent on never, ever repeating anything remotely like that time you ate a Naga Viper on a dare and may have blown actual steam out of your ears, there's only one rule that's 100% guaranteed to keep you safe: There's nothing wrong with ordering the grilled cheese.