Dry earwax can hint at less underarm odor
The clue is dry, flaky earwax. People with this earwax type often carry a version of the ABCC11 gene that is linked to much less underarm odor. The same genetic variant influences both traits, making earwax a visible hint—not a perfect test—of what is happening elsewhere in the body.
One gene affects two kinds of secretions
The ABCC11 gene helps control the movement of certain molecules into bodily secretions. A common variant reduces that activity. In the ear, it tends to produce dry, crumbly wax rather than the wetter, stickier type. In the armpit, it means less of some odor-producing material is released in the first place.
Underarm sweat itself is mostly water and salts and is not necessarily smelly. Odor develops when bacteria on the skin break down compounds in secretions from apocrine glands, which become active around puberty. With fewer of those compounds available, there is less for bacteria to turn into characteristic body odor.
A tendency, not a guarantee
Having dry earwax does not mean someone will never smell or never need deodorant. Sweat, skin bacteria, clothing, activity, and individual biology all affect odor. The genetic variant changes the odds and can make odor much milder; it does not switch off sweating or eliminate every source of smell.
The striking connection is that a small difference in one gene can show up in two seemingly unrelated places: the texture of wax in the ear and the amount of odor-producing material released under the arms.
