Foot odor is a unpleasant, often strong, smell that comes from the feet of many people. Some people describe the smell as being like cheese, sulfur, vinegar or ammonia, but most are in agreement that the smell is very bad! If you have ever had, or stood next to someone with, foot odor you may have wondered what causes the horrible smell.
Why do feet smell so bad?
Even though sweat does not have an odor it is the main cause of smelly feet. The sweat on the feet provides the perfect environment for bacteria to grow and some of these bacteria create the bad smelling substances associated with foot odor. These bacteria are always on human skin without causing problems, but an increase in sweat allows them to multiply quickly. Certain conditions such as wearing socks and/or shoes without ventilation can increase sweat, which increases the bad smell further.
The main bacterial cause of foot odor comes from a species of bacteria known as brevibacterium linens. These bacteria eat the dead skin on the feet and convert methionine into methanethiol, which has a sufur smell. Interestingly, brevibacteria are responsible for the strong smell in many cheeses!
Other cases of foot odor comes from another group of bacteria called Propionibacteria, which break down amino acids into propionic acid. This acid is chemically similar to the acid found in vinegar. Another bacteria responsible for smelly feet is Staphylococcus epidermidis, which creates the strong smelling Isovaleric acid from the amino acid leucine. Both Propionibacteria and Staphylococcus epidermidis are used in cheesemaking!
Preventing smelly feet
There are hundreds of different methods and remedies for preventing or getting rid of foot odor. However, one of the cheapest and most effective is baking soda (sodium bicarbonate). The baking soda creates a less hospitable area for the bacteria to grow. A light dusting on the feet, as well as in your socks and shoes, is usually enough to prevent the smell.