Laurie Noro – The scientific news agency specialized in debunking rumors

Science. Hair removal, shaving and laser treatment: all methods are good for getting rid of hair. Besides the fashion of the moment, does this hair still have its raison d’être, or is it an ancestral relic? Sweep the rumor detector through the command.

Our hair history

When compared to other mammals, humans have very little hair. Their closest cousins, the great apes, have their skin completely covered in fur. When and why did we lose our hair? Perhaps about 1.6 million years ago, when humans began to walk long distances. To avoid overheating during strenuous commutes, he needed to find a more efficient way to regulate his body temperature. Fur is an excellent thermal insulator, especially in winter, but it is not very effective at dissipating excess heat.

Then evolution preferred the elimination of sweat by apocrine glands located on the surface of the skin. So our ancestors gradually got rid of these thick hairs that impeded the evaporation of sweat.

What about today when we added a few layers of clothes to that? Before you take out the shaver, you should know that hair has other functions.

Poetry roles

On the one hand, the tiny hairs that cover our bodies are excellent mechanoreceptors. This means that this fine drip detects stimuli on the surface of the skin and relays the message to the brain. A 2011 study claimed that people with hair spotted insects on their bodies faster than participants without hair. In this hypothesis, the hair will have a defensive function against the parasites that live on the surface of our skin.

On the other hand, the bottom will also have a role in regulating body temperature, but its role is rather insignificant. Explanation: Hair is born in the hair follicle, which is a cavity located just below the surface of the skin.

This is where two other glands are located: the sebaceous gland and the apocrine gland. The first moisturizes and protects the skin from external aggressions. The second is responsible for regulating body temperature in most mammals. When we get rid of hair, for example during laser hair removal, these two glands are also damaged. The destruction of the apocrine glands will not interfere with effective perspiration because this task now falls to the apocrine glands in humans. As for the sebaceous glands, laser hair removal will reduce their size. However, it is not known if this affects skin hydration.

The effect of shaving is also less, as it involves cutting the hair on the surface of the skin, while leaving the hair follicles intact.

Rule

By promoting the evaporation of heat through the apocrine glands, humans were able to shed their fur. Even if he leaves hair on some parts of his body, it is no longer necessary to regulate his body temperature … although it can sometimes be useful to “feel” a parasite.