Why does the sweat from our armpits stink?


Why does the sweat from our armpits stink?

In: Biology

Sweat doesn’t smell but the bacteria that builds up in a warm damp place does which is why the armpit can still smell even when there’s no sweat.

Two types of sweat glands. One kind only really develops in the pits/groin. These glands secrete a protein in the sweat. Bacteria feed off the protein and their secretions create the smell.

In certain people, a particular variation in a gene called ABCC11 results in excess production of proteins and oils the secretions of oil glands in the skin.

For reasons that aren’t quite clear, this encourages the growth of certain types of bacteria, especially in warm, damp, sheltered areas of the body. The armpits for example. Theses bacteria digest proteins and fatty acids in body oils, and produce certain smelly byproducts, especially from sulfur containing amino acids in proteins.

People who have a certain variation in ABCC11 have reduced production of oil in their skin and reduced protein secretions from oil glands. They generally don’t need deodorant, may be less prone to acne. However they suffer from dry skin and a dry form of ear wax that can lead to wax plugs, resulting in hearing loss and ear infections.

This variation is somewhat uncommon in Europeans, but very common among Asians which is why deodorant isn’t usually found in stores there. It is also common in certain parts of Africa.