Why Mint Feels Cold & Other Flavour Mysteries

There’s no doubt that when it comes to dental products, mint is the dominant flavour choice. Finding a toothpaste or mouthwash that isn’t spearmint, peppermint, or some made-up version of mint (like an arctic blast) is a challenge. The fact is, these products don’t actually need this flavouring to do their work. Which may leave you wondering: Why does mint flavour make your mouth feel cool and fresh as if your toothpaste was extra effective?

It comes down to a plant’s ability to trick your brain through chemistry. All varieties of mint plants produce a chemical called menthol. This is the substance that gives mint its distinctive flavour. Your body senses cold when a protein called TRPM8 is activated in your nerve cells, which then relay a current signal to your brain that it interprets as a cold sensation. Menthol has the unique ability to activate TRPM8, tricking your nerves into thinking they’re feeling cold when they’re actually not.

Hot peppers make you feel the sensation of heat pretty much the same way. Most hot or spicy foods contain a chemical called capsaicin. This chemical tricks your brain into feeling hot by activating a different protein, called VR1. Because both menthol and capsaicin mess with your temperature sensitivity, they can make you feel numb. That’s why you’ll find them in topical painkillers from the drugstore.

There’s no doubt that mint can help alleviate bad breath, but it also makes you feel extra clean. So why do we associate being cold with healthy teeth? We may never know the scientific reason, but one thing we do know is that when your mouth is dry at warm you can practically feel the bacteria growing, covering your tongue, teeth and gums in the muck. It makes sense then that the opposite sensation with signify health. Also, mint has the added benefit of stimulating the production of saliva, which helps wash teeth and remineralize your enamel. This is one reason chewing mint-flavoured sugar-free gum can be good for your teeth.

And not to worry if you don’t like mint flavour. You can still take great care of your dental health using toothpaste in other flavours such as cinnamon or bubble gum.