February 18, 2008...9:36 pm
Did you know…
Did you know…
Why mint provides a cold sensation?
Well well… Have you ever wondered about that? I didn’t either, until today when I fell on an article in Science & Vie. I think that my subscription ends this month… but I haven’t received the January 2008 one either. Hmmm… Should talk to Mom about that 
Anyway, I’ll try to make it as simple as possible 
According to the article, it’s because of menthol, an organic compound which the 7800 varieties of mint contain. (My my, there are 7800 varieties 
) Consisting of 10 carbon atoms, 20 hydrogen one and 1 oxygen, this hydrocarbon of the same chemical family as camphor, makes the undisputed success of candy mint and refreshing balms, tooth pastes and other perfumes. Extracted from Japanese mint oil from the beginning of the 20th century, menthol is today obtained synthetically… because of the great demand… 10 000 tons per year…
But let’s come back about that sensation… (Now I want to eat a mint Wonderbar… ) of cold from mint. Would you believe it? It’s only in 2002 that David Julius, a neurobiologist discovered this ‘mechanism’ at the university of California in San Francisco. It all comes from the fact that, on our tongue and skin, we have small nervous cells (cells are already small, aren’t they?) more sensitive to temperature that others, the thermo receptors. Some are sensitive to heat and others to cold and some others to both.
David Julius discovered that the neurons sensitive to cold had been given a receptor (God is great ) which he named… TRPM8. which it stands for, I have absolutely no idea In studying this receptor in vitro, he saw that a menthol molecule acted on the receptor, triggering a nerve impulse through the neurons to the brain. TRPM8 (I’m having a really hard time typing that name 
) converts thermal or chemical stimulus into electrical signal. In reality, menthol doesn’t provide that cold. When we have a mint candy, the temperature in our mouth doesn’t go down…
But… in activating that receptor, the menthol deceives our brain, making us think we are experiencing the cold. After this demonstration, David Julius showed that in spring, this receptor was also responsible of the “true” sensation of cold in vivo in mammals. For that, he eliminated from the genome of mice, the gene responsible for that feeling. These mice actually could walk on ice, which these rodents will in normal cases, refuse.
David Julius had already shown some years before that capsaicin, a molecule present in chilly was responsible for that burning sensation…
A great man indeed 
P.S. Hoping that I have not made any mistakes I am not a chemistry girl Nor a biology one…
11 Comments
February 18, 2008 at 10:04 pm
I’ve never been a fan of chocolates containing mint but i absolutely looovee toothpastes which have the strong mint feel. It great to know why we feel that way now!
makes sense… 
February 18, 2008 at 10:06 pm
Interesting
zamais mo ti conne sa!
Ps : mint wonderbar trop trop bon
February 18, 2008 at 10:41 pm
Yo! I was a SVJ subscriber until 08!
Came to know about the menthol in one of the hors-séries i think!
February 18, 2008 at 11:39 pm
I love fresh mint, I like to crunch it up in my hand and the smell is so fresh and strong. You will have to speak to your mom to get this years subscription up to date, so much more to learn and share! ;o)
February 19, 2008 at 2:18 am
Oh, that candy looks sooooo good!
February 19, 2008 at 4:41 am
Interesting stuff and I love love love your photo!
February 19, 2008 at 8:30 pm
Interesting read!
Note to the guys reading this. Apparently mint adversely affects the male reproductive system. Watch your chewing on those “bonbon la mente”
February 20, 2008 at 5:30 pm
February 20, 2008 at 7:50 pm
Never been too much of mint choco fan, but never did all those stuff!!! Interesting, i need to say
February 20, 2008 at 9:04 pm
Hei Nus
Aaah, minty chocolate….
Yummy!!
Lol
February 21, 2008 at 7:06 am
We don’t have mint Wonderbars here. We have Peanutbutter Wonderbars, do you have them? That is a great description. I just assumed it was an exothermic reaction causing it. I am a food scientist, so knew about the capsicum but since I have been out of the loop for awhile didn’t know about the reason for the cool feeling of mint.
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