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?

10 Rad Gifts for Hikers

Greg Rosenke/Unsplash
Greg Rosenke/Unsplash

The popularity of bird-watching, camping, and hiking has skyrocketed this year. Whether your gift recipients are weekend warriors or seasoned dirtbags, they'll appreciate these tools and gear for getting most out of their hiking experience.

1. Stanley Nesting Two-Cup Cookset; $14

Amazon

Stanley’s compact and lightweight cookset includes a 20-ounce stainless steel pot with a locking handle, a vented lid, and two insulated 10-ounce tumblers. It’s the perfect size for brewing hot coffee, rehydrating soup, or boiling water while out on the trail with a buddy. And as some hardcore backpackers note in their Amazon reviews, your favorite hiker can take the tumblers out and stuff the pot with a camp stove, matches, and other necessities to make good use of space in their pack.

Buy it: Amazon

2. Osprey Sirrus and Stratos 24-Liter Hiking Packs; $140

Amazon

Osprey’s packs are designed with trail-tested details to maximize comfort and ease of use. The Sirrus pack (pictured) is sized for women, while the Stratos fits men’s proportions. Both include an internal sleeve for a hydration reservoir, exterior mesh and hipbelt pockets, an attachment for carrying trekking poles, and a built-in rain cover.

Buy them: Amazon, Amazon

3. Yeti Rambler 18-Ounce Bottle; $48

Amazon

Nothing beats ice-cold water after a summer hike or a sip of hot tea during a winter walk. The Yeti Rambler can serve up both: Beverages can stay hot or cold for hours thanks to its insulated construction, and its steel body (in a variety of colors) is basically indestructible. It will add weight to your hiker's pack, though—for a lighter-weight, non-insulated option, the tried-and-true Camelbak Chute water bottle is incredibly sturdy and leakproof.

Buy it: Amazon

4. Mappinners Greatest 100 Hikes of the National Parks Scratch-Off Poster; $30

Amazon

The perfect gift for park baggers in your life (or yourself), this 16-inch-by-20-inch poster features epic hikes like Angel’s Landing in Zion National Park and Half Dome in Yosemite National Park. Once the hike is complete, you can scratch off the gold foil to reveal an illustration of the park.

Buy it: Amazon

5. National Geographic Adventure Edition Road Atlas; $19

Amazon

Hikers can use this brand-new, updated road atlas to plan their next adventure. In addition to comprehensive maps of all 50 states, Puerto Rico, Canada, and Mexico, they'll get National Geographic’s top 100 outdoor destinations, useful details about the most popular national parks, and points on the maps noting off-the-beaten-path places to explore.  

Buy it: Amazon

6. Adventure Medical Kits Hiker First-Aid Kit; $25

Amazon

This handy 67-piece kit is stuffed with all the things you hope your hiker will never need in the wilderness. Not only does it contain supplies for pain, cuts and scrapes, burns, and blisters (every hiker’s nemesis!), the items are organized clearly in the bag to make it easy to find tweezers or an alcohol wipe in an emergency.

Buy it: Amazon

7. Hiker Hunger Ultralight Trekking Poles; $70

Amazon

Trekking poles will help increase your hiker's balance and stability and reduce strain on their lower body by distributing it to their arms and shoulders. This pair is made of carbon fiber, a super-strong and lightweight material. From the sweat-absorbing cork handles to the selection of pole tips for different terrain, these poles answer every need on the trail. 

Buy it: Amazon

8. Leatherman Signal Camping Multitool; $120

Amazon

What can’t this multitool do? This gadget contains 19 hiking-friendly tools in a 4.5-inch package, including pliers, screwdrivers, bottle opener, saw, knife, hammer, wire cutter, and even an emergency whistle.

Buy it: Amazon

9. RAVPower Power Bank; $24

Amazon

Don’t let your hiker get caught off the grid with a dead phone. They can charge RAVPower’s compact power bank before they head out on the trail, and then use it to quickly juice up a phone or tablet when the batteries get low. Its 3-inch-by-5-inch profile won’t take up much room in a pack or purse.

Buy it: Amazon

10. Pack of Four Indestructible Field Books; $14

Amazon

Neither rain, nor snow, nor hail will be a match for these waterproof, tearproof 3.5-inch-by-5.5-inch notebooks. Your hiker can stick one in their pocket along with a regular pen or pencil to record details of their hike or brainstorm their next viral Tweet.

Buy it: Amazon

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Coca-Cola Is Discontinuing TaB After Almost 60 Years

Stock up while you can.
Stock up while you can.
lokate366, Flickr // CC BY-SA 2.0

In 1963, Coca-Cola debuted TaB, a one-calorie diet soda that came in a pink can and promised women the chance to “have a shape he can’t forget.” The beverage was intended, as the commercial’s catchy jingle was quick to remind you, “for beautiful people,” with the sunny implication that sipping it could make you one of them.

TaB began to lose popularity after Diet Coke was launched in 1982, but a small crop of devotees still prefer it today. There’s even a website called ilovetab.com that keeps tabs on where the beverage is sold and which celebrities are spotted with a can in hand.

Unfortunately for fans, the Coca-Cola Company has finally decided to discontinue the drink just a few years short of its 60th anniversary. It’s not the only casualty: ZICO coconut water, Odwalla juices, Diet Coke Feisty Cherry, and Coca-Cola Life (a reduced-sugar version of Coke with stevia leaf extract) are also being retired, along with a few regional and international products.

Though plenty of businesses have scaled back their offerings—or gone bankrupt—due to the coronavirus pandemic, the company maintains that these changes were in the works long before then. That said, “the ongoing COVID-19 supply chain challenges and shifting shopping behaviors prompted the company to fast-track its plan,” Coca-Cola explained in a press release.

TaB is now more of a nostalgic cult classic than a lucrative asset. According to The New York Times, Coca-Cola circulated about 3 million cases of TaB in 2011—not even half a percent of the number of Diet Coke cases produced in the same year. But that’s not to say people won’t be sad to see it go.

“We’re forever grateful to TaB for paving the way for the diets and lights category, and to the legion of TaB lovers who have embraced the brand for nearly six decades,” Kerri Kopp, Diet Coke’s group director for North America, said in a press release. “If not for TaB, we wouldn’t have Diet Coke or Coke Zero Sugar. TaB did its job.”

[h/t The New York Times]