Hanging out with some friends the other night, and as bedtime rolls around, I hear my friend say to her son, "Come on, time to get minty."
I had never heard this before, but I knew exactly what it meant. I was excited at the novelty of it, but also that it makes brushing your teeth sound like way more fun than "brushing your teeth."
I was also set wondering why I had never heard this before; it makes so much sense. But my next thought is the one that took hold – why is toothpaste minty?
Today I'm here to tell you why toothpaste is minty; there’s two reasons. One of them makes sense and the other does not.
The easy answer for why toothpaste to this day remains minted lies in the trigeminal properties of mint. The trigeminal sense is not so much a sixth sense, but more like 5 1/2. When things are sensed as spicy-hot or minty-cool, that is the trigeminal sense being activated. This effect creates a habit cycle by making you think your breath is fresh after brushing because your mouth feels cooler.
That's a good reason. But there are other things that produce trigeminal effects. Jalapeno peppers would make a good toothpaste on this account. (Why does it have to be cool?) Then there's cardamom seeds. And fennel. Why isn't toothpaste made of liquorice?
Coincidence, that's why. Mint just happened to be the flavor of the toothpaste to land on Claude Hopkins doorstep. He is advertising's first master manipulator, and the man responsible for the reason we brush out teeth.
I know this might sound crazy, but prior to Pepsodent in the 1900's, people did not brush their teeth. Crazy. We had to be duped into it by a marketing campaign. And dupe he did – 100 years later, here we are, still getting minty before bedtime, every night.
It is unclear as to whether Hopkins knew the power of trigeminal effects in creating a habitual feedback loop. But he definitely understood the concept of the loop.
When his client came to him for help selling his new tooth-paste product, Hopkins spent hours and hours reading about dentistry and oral hygiene, until one small illustration struck him.
A page in the book indicated that there is a film that forms on the surface of your teeth, and all over your mouth. In the dental textbook it's called mucin plaque, but he called it "the film." The film is always there, and it's always been there. But Hopkins was a mental manipulator maximus.
He transformed that factoid thus:
You – run your tongue over your teeth, you feel that? That's a film of gross nasty schmutz that accumulates on your teeth every day. It's gross, and it also makes your breath smell. You like that filthy mouth film? No, no you don't. So why don't you get yourself a tube of Pepsodent, and scrub it right off. There. Feel that mint-flavored freshness? There, all better.
Feeling the film on your teeth was the cue, and having a fresh mouth was the reward. These two work together to rewire your brain until we have a habit. For things like nicotine and smoking, the cue is a physiological imbalance, because nicotine is addictive. But for other things that are not drugs, we must create a habitual loop.
Claude Hopkins knew this, and with this knowledge he set a civilization on the path to oral health. The fact that this path was minty fresh was kind of inconsequential. And since we're here talking about this, I should add that in India, where mouth health has been a big deal for much longer than toothpaste, they have a few different approaches. Cardamom, fennel, and fenugreek are sometimes roasted, sometimes candy-coated, but usually chewed after a meal.
Would fennel toothpaste ever take off? I'll keep my eye out the next time I'm in Trader Joe's, or that little Vermont grocery store.
And now for the final reveal, the first Pepsodent wasn’t even made with Mint, it was made with Sassafras (think Root Beer). I will assume this was categorized as “minty.” I’m also having a fuzzy recollection that Burt’s Bees makes a clove toothpaste?
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Charles Duhigg for Slate
Charles Duhigg wrote a book about habit formation, called The Power of Habit. I wrote about Charles's book in my book called Hidden Scents.