The human body is capable of expelling various offensive aromas (something we’re all unfortunately extremely familiar with). But which of the two most prevalent stenches is the most unpleasant: Body odor or bad breath? Let’s take a scientific look to crown the officially nose-wrinkling king of stink.
What Causes Body Odor
The short answer is bacteria. Lingering in your moist crevices, they break down odorless compounds in sweat known as thioalcohols, which are zesty chemicals similar to those found in onions and meat (that’s why your gym bag smells like day-old grilled onions). “These odorless molecules come out from the underarm, they interact with the active microbiota, [and] they’re broken down inside the bacteria,” Dan Bawdon, a postdoctoral researcher at the University of York in England, explained to NPR. Or, in layman’s terms, bacteria devour your surprisingly odorless sweat, then metabolize it into nasty-smelling thioalcohols (thanks a bunch, bacteria).
Thioalcohols are also volatile compounds, which allows them to easily become vapors or gases, meaning they’re ideal candidates for producing pungent, spreadable smells. To make matter worse, armpits also contain apocrine glands—the glands that produce that oily, smelly form of sweat you secrete when stressed.
What Causes Bad Breath
Dr. Corbin Brady, dentist at Brady Dental Care, previously told us that bad breath is also caused by bacteria. “The bacteria within your mouth produces smelly by-products,” he explained. More specifically, the bacteria that help digest our food produce hydrogen sulfide (which smells like rotten eggs) and methyl mercaptan (which smells like rotten cabbage). These bacteria inhabit the gaps between the gum and tooth, as well as in the scattered crevices along the tongue, which is why it’s extra important to brush your tongue along with your teeth if you’re hoping to ward off bad breath.
Which Is Worse
While old onions, rotten eggs and rancid cabbage emanate equally unpleasant aromas, celebrity matchmaker Alessandra Conti believes body odor beats out bad breath on a scale from “pleasant” to “burn-my-nose-off-my-face-before-I-vomit,” and for good reason: “Body odor is worse than having bad breath, because bad breath is easily fixable,” she explains. “If your date has unpleasant breath, you can simply offer them a piece of gum or a mint. Body odor, however, is a much more difficult problem to alleviate: When a person has noticeable body odor that’s nauseating, there is very little that their date can do without completely offending the person.”
But that’s not the only reason body odor beats out bad breath, according to Conti. “It’s also scientifically proven that smell is a subliminal way that our bodies select the people with whom we are in relationship with,” she adds. “When a person is repulsed by another person’s body odor, that’s a great indicator that they may not be the best biological match.”
So, there you have it: If you happen to find yourself in the rare situation where you have to choose between deodorant and toothpaste, pick the deodorant. Everyone in your vicinity will greatly appreciate it.