Body odor from a scientific perspective

Most of us are sensitive to body odor, even a light breath can identify the unpleasant odor. Inside the smell is a very complex mechanism influenced by genes, age, diet and personal hygiene. So what exactly is body odor? Where does it come from? And what can we do about it?

Why is there body odor?

To get started, you only need two things to create that familiar scent: sweat secreted under the armpits and the number of bacteria living on it. Most people release body odor through sweat and that's the point. Your body has millions of sweat glands, divided into two main types:

1. Eccrine sweat glands, distributed over the skin, secrete mainly water and salt.
2. Apocrine sweat glands develop during puberty, under the armpits and several other places on the body.

We are all sensitive to body odor.

The sweat that Apocrine glands secrete is mostly protein and fat. This type of sweat usually does not smell if no bacteria are present. Every square centimeter of our body is covered by thousands of bacteria. Many microorganisms thrive in moist environments, such as armpits. The bacteria here can reach millions of fish per square centimeter, one of the highest densities of the entire skin.

Hidden deep in this group of microorganisms are Corynebacteria, Staphylococci, Micrococci. These bacteria survive on the amount of protein and fat in sweat. They turn odorless compounds into new compounds that smell very unpleasant. One of the biggest factors is probably the sulfur-containing compound that makes the body odor smell like onions and carboxylic acid, the compound that creates the cheese smell.

These molecules radiate from under the armpits and can enter the nose, where they are trapped and immediately discovered by special receptors. We can identify odor causing molecules at a density of

So, what determines how strong your body odor is?

Most people release body odor through sweat.

Body odor varies from person to person, depending on the number of microorganisms that live under the armpits and the nutrients that sweat glands provide them. The genome also helps determine what kind of compound you secrete, in how much, adrenaline increases your rate of head sweating, so your body odor may become stronger when you're worried. The structure and density of bacteria also vary from person to person and play an important role. Even the food you eat creates small effects.

So how do you deal with body odor?

Underarm hygiene with improved soap and water but does not remove bacteria because there are still many hidden beneath the deeper skin layers. Deodorants prevent bacteria from working at the same time, creating a deodorizing layer. Antiperspirants create sweat glands that block the armpits.

While we continue the war, scientists still try to understand it. We don't know why the brain is often bothered by these particular odors. But many theories suggest that the smell of sweat from underarms may have positive functions such as tightening social ties and providing a special communication tool.

1. Why do we not feel our body odor?
2. 5 surprising things you didn't know about body odor