You just brushed your teeth. Feel cool. He takes a sip of water, but it’s cold. Your next breath also tastes fresh. After all, what did the toothpaste do to your mouth? Could it be a trick to help you feel cooler when you really need it?
O bulba natural compound that comes from mint plants, is the ingredient in toothpaste that creates the cold sensation.
Menthol activates the TRPM8 receptors in the nerve endings in the mouth, which are the same receptors responsible for detecting cold. Thus, menthol essentially tricks your brain into feeling cold.
It does this by binding to TRPM8 receptors and changing their shape, allowing calcium to enter and trigger a signal to the brain, which is interpreted as a feeling of cold.
When you drink water or breathe in air with menthol in your mouth, the menthol spreads everywhere and more receptors are activated, increasing its effect. The receptors are open and prepared to feel cold, so any liquid or air that is even slightly cool will feel even colder than it actually is.
Why is menthol in so many products?
Companies use this action of menthol to create another dimension in the taste and sensation of their products.
Menthol is added to toothpaste and chewing gum to create a cool, refreshing sensation that signals “cleanliness”and cough drops to create the sensation of open airways.
O Menthol does not physically cause decongestion — it only increases sensitivity and the feeling of freshness in the airways, which makes it seem like more air is passing through.
The menthol it can also cool the skin through the same receptors. This is why it is often added to topical creams designed for pain relief.
The cooling sensation of menthol can also act as a “counter-irritant”in which menthol activates pain receptors in the skin causing irritation and then desensitizes them, which can reduce underlying pain.
Studies have shown that topical menthol can be an effective treatment for pain caused by muscle pain, neuropathic pain related to cancer treatments, and migraines.
Menthol as a sports supplement
The cooling effect of menthol can even be beneficial for exercise and sports.
In a study in 2015 in Medicine and Science in Sports and detailed by researchers in an article in , a menthol mouthwash was found to reduce runners’ feelings of heat and allow them to run faster in a five-kilometre time trial at 33°C.
Interestingly, menthol mouthwash was more effective than drinking slush, which physically reduced body temperature but didn’t make runners feel cooler or run faster.
So how hot you feel may be more important than how hot you are — at least for running performance.
The Australian Institute of Sport has classified menthol as a group B sports supplement, meaning it has “emerging and/or mixed scientific support, deserving consideration in specific populations or situations”.
Research has now focused on adding menthol to energy gels.
In a more recent one (from 2020), the same team tested energy gels with different concentrations of menthol to determine the ideal amount to maximize the refreshing effect. The aim is to allow menthol to be more accessible during exercise and sport.
The use of menthol in sport is controversial because it can make a person feel cooler when exercising in the heat and allow them to go beyond their thermal limits. In theory, this could increase the risk of overheating and heat exertion-related illness — a continuum of conditions that ranges from muscle cramps to heat exhaustion to the potentially fatal condition of heat stroke.
However, this has not been a problem in published research to date. An international consensus statement concluded that menthol supplements are safe when prepared and used according to guidelines, and do not confer an unfair advantage or violate the spirit of sport.
It is likely that the use of menthol in products will become even more common in the future.
The next time you feel an unexpected sense of freshness from a food, drink or cream, the ingredient list will tell you if it’s the menthol playing tricks on you.
