Why Does Mint Make Your Mouth Feel Cold?

iStock/bhofack2
iStock/bhofack2

Reader Lisa from Anderson, California, wrote in with a question: "Chew a piece of mint gum and then drink something. It seems colder. Why is that?"

Mint gum or candy might make everything in your mouth feel sub-zero, but like the hot water that sometimes feels cold I wrote about in 2008, the feeling is just a thermal illusion that happens when our sensory receptors get fooled by stimuli.

At the heart of the minty matter is a protein called the transient receptor potential cation channel subfamily M member 8 (TRPM8), which is expressed in sensory neurons. TRPM8 is an ion channel, a type of protein that regulates the movement of ions across the membranes of cells. Just like only certain keys can open a lock on a door, only certain stimulants can open the ion channel and access the cell. TRPM8 opens in the presence of cold temperatures and allows Na+ and Ca2+ ions to enter the cell. This changes the electrical charge within the neuron and the information being sent from the neuron to the central nervous system, eventually leading to the perception of cold.

TRPM8 doesn't just respond to cold temperatures, though.

It also activates in the presence of menthol, a waxy, crystalline organic compound found in peppermint and other mint oils. (It responds to other "cooling agents," too, like eucalyptol and icilin. Why, exactly, is unknown; menthol just happens to fit the cellular "lock.") In the presence of menthol, TRPM8 ion channels open up the same way they would if the ambient temperature in your mouth dropped. The same "hey it's cold in here!" signal is sent to the brain, even though menthol doesn't actually cause the temperature in the mouth to change. And just like that, the wondrous human brain is tricked by a piece of Doublemint.

Even after you spit the gum out, a little menthol will remain and the sensory neurons will stay sensitized. Drinking anything cold or even taking in a big breath of cool air will cause the neurons to fire again, and the double whammy of the cool temperature and the menthol will make your mouth seem extra cold. Even a hot drink will seem weirdly cool and refreshing.

TRP-V1, another ion channel on the sensory neurons, displays a similar quirk. TRP-V1 is activated by hotter temperature, but also responds to capsaicin, the chemical responsible for the spiciness of hot peppers. This can cause even ice cold drinks to feel hot.

So what would happen if you ate a chili pepper that's been in the freezer, or a warmed up mint? Or ate a hot pepper and a cool mint at the same time? Would the hot and cold perceptions cancel each other out? To be honest, we're not sure. Has anyone ever tried this at home?

Kodak’s New Cameras Don't Just Take Photos—They Also Print Them

Your Instagram account wishes it had this clout.
Your Instagram account wishes it had this clout.
Kodak

Snapping a photo and immediately sharing it on social media is definitely convenient, but there’s still something so satisfying about having the printed photo—like you’re actually holding the memory in your hands. Kodak’s new STEP cameras now offer the best of both worlds.

As its name implies, the Kodak STEP Instant Print Digital Camera, available for $70 on Amazon, lets you take a picture and print it out on that very same device. Not only do you get to skip the irksome process of uploading photos to your computer and printing them on your bulky, non-portable printer (or worse yet, having to wait for your local pharmacy to print them for you), but you never need to bother with ink cartridges or toner, either. The Kodak STEP comes with special 2-inch-by-3-inch printing paper inlaid with color crystals that bring your image to life. There’s also an adhesive layer on the back, so you can easily stick your photos to laptop covers, scrapbooks, or whatever else could use a little adornment.

There's a 10-second self-timer, so you don't have to ask strangers to take your group photos.Kodak

For those of you who want to give your photos some added flair, you might like the Kodak STEP Touch, available for $130 from Amazon. It’s similar to the regular Kodak STEP, but the LCD touch screen allows you to edit your photos before you print them; you can also shoot short videos and even share your content straight to social media.

If you want to print photos from your smartphone gallery, there's the Kodak STEP Instant Mobile Photo Printer. This portable $80 printer connects to any iOS or Android device with Bluetooth capabilities and can print whatever photos you send to it.

The Kodak STEP Instant Mobile Photo Printer connects to an app that allows you to add filters and other effects to your photos. Kodak

All three Kodak STEP devices come with some of that magical printer paper, but you can order additional refills, too—a 20-sheet set costs $8 on Amazon.

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Why Do We Say ‘Spill the Beans’?

This is a Greek tragedy.
This is a Greek tragedy.
anthony_taylor/iStock via Getty Images

Though superfans of The Office may claim otherwise, the phrase spill the beans did not originate when Kevin Malone dropped a massive bucket of chili at work during episode 26 of season five. In fact, people supposedly started talking about spilling the beans more than 2000 years ago.

According to Bloomsbury International, one voting method in ancient Greece involved (uncooked) beans. If you were voting yes on a certain matter, you’d place a white bean in the jar; if you were voting no, you’d use your black bean. The jar wasn’t transparent, and since the votes were meant to be kept secret until the final tally, someone who accidentally knocked it over mid-vote was literally spilling the beans—and figuratively spilling the beans about the results.

While we don’t know for sure that the phrase spill the beans really does date all the way back to ancient times, we do know that people have used the word spill to mean “divulge” at least since the 16th century. The Oxford English Dictionary’s earliest known reference of it is from a letter written by Spanish chronicler Antonio de Guevara sometime before his death in 1545 (the word spill appears in Edward Hellowes’s 1577 translation of the letter).

Writers started to pair spill with beans during the 20th century. The first known mention is from Thomas K. Holmes’s 1919 novel The Man From Tall Timber: “‘Mother certainly has spilled the beans!’ thought Stafford in vast amusement.”

In short, it’s still a mystery why people decided that beans were an ideal food to describe spilling secrets. As for whether you’re imagining hard, raw beans like the Greeks used or the tender, seasoned beans from Kevin Malone’s ill-fated chili, we’ll leave that up to you.

[h/t Bloomsbury International]