What does your earwax have to do with your stinky B.O.?
I’m Anna Rothschild, and this is Gross Science.
Human earwax has a variety of purposes.
It’s used to flush dead skin cells out of the ear, and also to prevent foreign objects,
like dust, from getting into the ear.
It even contains some antimicrobial properties to potentially keep out bacteria and other
pathogens.
But not all earwax is created equal.
Human beings actually have two varieties of earwax.
Most people of Caucasian or African descent have wet-type earwax, which is sticky and
yellow or brownish.
(That’s the kind I have.)
But most people of East Asian descent have dry-type earwax, which appears light and flaky.
These earwax traits are caused by different variants of the same gene.
The wet-type is probably the ancient form, while the dry-type is a variant that arose
later, likely in a population of early humans who had migrated to northern and eastern Asia.
The interesting thing is that the type of earwax you have is correlated with how stinky
you are.
Earwax is secreted in part by modified apocrine glands, which are one of the glands that release
sweat.
Apocrine sweat is especially delicious to bacteria, who release that gross B.O.
scent after they chow down on it.
And, some small studies have found that people with wet-type earwax also have more body odor.
Earwax itself has a scent, too.
Scientists have said that it smells acidic, fecal, and like sweaty feet.
Yum.
But the amount of odor differs between people.
In one small study, researchers measured the amount of volatile organic compounds in earwax
from people of African, Caucasian, and Asian descent.
Turns out, each group had different amounts of these smelly compounds.
This might sound silly, but earwax could one day help researchers learn more about you
than just your race or ethnicity.
We could potentially use it as a non-invasive way to diagnose disease.
We already know that certain conditions, like maple syrup urine disease, can be detected
through the smell of earwax earlier they can be identified by other methods.
Earwax might even be able to track where we’ve been—after all, a big part of its job is
to trap particles from our environment, which might provide clues to where we’ve spent
our time.
And it contains a lot of fats, which are great at holding on to certain types of chemicals.
But more research needs to be done to determine just how long our earwax might hold on to
that material.
Especially since many of us clean our ears on a regular basis.
Whales, however, don’t have that luxury.
Their earwax builds up for years, and each layer of it corresponds to about six months
of a whale’s life.
Consequently, it can be used almost like tree rings to glean detailed information about
an individual whale.
For example, scientists have used a foot-long plug of earwax to determine when a particular
blue whale was exposed to different pollutants.
So far, we haven’t been able to do anything similar with human earwax.
But it could help us track an ancient human migration.
Native Americans also frequently carry the gene for dry earwax, supporting the idea that
their ancestors migrated from Siberia.
Who knew we could learn so much from this one bodily secretion?
Ew.