Peppermint is everywhere this time of year, decorating our Christmas trees and dangling from the corners of our mouths as candy canes. We crave its unique sensation of coldness, but exactly what causes that?
Science can answer that.
It's the menthol in peppermint that makes it feel so cold, even when it isn't. And we now know that menthol actually fools our brain into thinking peppermint is cold because of the nerves it activates there: the same nerves associated with the sensation of cold.
A neurobiologist, David McKemy, at the University of Southern California recently figured this out and created a video explaining how menthol, particularly in peppermint, works to create that coldness.
In his research, McKemy and his team used menthol in understanding how our brains detect the difference between hot and cold and how it reacts to those sensations. In their findings, they discovered a protein in menthol that sends an electrical signal to the brain alerting it of coldness. The brain responds with the cold sensation in the nerve receptors in the mouth.
"It's incredible how nature and plants have evolved to have these effects," says McKemy.
Although science can't tell us why, we love the cold sensation in the mouth that menthol brings. That's why it's a popular ingredient not just in peppermint, but also in over-the-counter cough medicines and cigarettes. Earlier research, though, does point out that this sensation quenches thirst (which is why cold water always taste better than warm) and makes breathing easier.
As to why we have peppermint this time of year, the answer is more historical. Before air conditioning, candy makers created their candy in the winter, when the sugary concoctions were less likely to melt during their creation. At some point, probably in the 17th century, we believe that one candy maker decided to shape peppermint into a cane shape to represent a shepherd's cane, reminding children of the Nativity.
Peppermint is a historically popular candy flavor because it's one of the few flavors that doesn't fade when cooked, a process necessary for making candy. That's why some of the oldest candies we're aware of usually had mint-based flavors.
Peppermint is also thought to have health benefits. Although scientific research is still lacking in this area, most experts believe it relieves indigestion, soothes certain skin conditions and that the menthol in it helps relieve congestion caused by colds. There is also current research investigating the potential anti-cancer effects of peppermint.
[Photo Credit: Lauren Manning/Flickr]