The Science of Skin

Some background knowledge of the science of skin can help you better understand how it adapts to changes and restores its balance when needed. And if you were more interested in history than biology in school (or even more interested in extracurricular activities), don't worry: we've filtered out the extraneous information and are focusing exclusively on skin care topics.

This article highlights the central structures of the largest body organ, their roles and processes.

The layers of skin

Your skin is made up of three primary layers. The subcutaneous tissue, also known as subcutaneous tissue, is the deepest of these components - a layer of fatty tissue that acts as a heat insulator to protect the body from extreme temperatures and store energy. (The subcutis contains half of all body fat.) This layer also contains loose connective tissue that connects the skin to the underlying muscles and bones.

The middle layer is known as the dermis and is largely made up of dense connective tissue that provides structure. There are also sebaceous glands, sweat glands, hair follicles, nerves and blood vessels here. The dermis contains a protein called collagen, which gives the skin its flexibility and resilience.

The epidermis is the outer layer of the skin, and the thinnest of the three. In addition to regulating transepidermal water loss - described in more detail below - it serves as a barrier to protect the skin from heat and cold, UV radiation, pollutants and pathogenic microorganisms that could cause disease or infection.

The epidermis is often referred to as "thin," but its thickness varies depending on the level of protection a particular part of the body requires - think, for example, the skin of the palms or soles of the feet compared to the skin of the eyelids or lips.

A closer look at the epidermis

The formulation of most skin care products meets the needs of the epidermis, which can be divided into further layers. We focus primarily on the horny layer (stratum corneum) and the hydrolipid film (protective acid mantle).

The horny layer

As the primary barrier of the skin, the stratum corneum consists of horny cells (flat, dead cells that primarily consist of the protein keratin) in a lipid matrix. The structure can be compared to a brick wall: the horn cells are the bricks, the lipids are the mortar. This composition gives the stratum corneum its impressive barrier properties.

Cells that originate in the innermost layers of the epidermis move upward – or outward – until they reach the stratum corneum. Here the dead cells are shed or detached. This process is called desquamation.

The hydrolipid film

The hydrolipid film is composed of water, sweat and lipid-containing sebum and acts as an external barrier. Although it cannot be seen with the naked eye, it extends over the entire surface of the skin - as a kind of backup for the stratum corneum, as it protects it from bacteria and foreign substances. Its job is also to maintain the elasticity of the skin by locking in moisture.

The biological aging process or excessive cleaning can have an impact on the hydrolipid film. In turn, transepidermal water loss can be reduced if this layer is in a healthy condition.

'Hydrated' and 'moisturized' are considered synonyms, but in the context of skin care, 'hydration' describes the skin's water content, while 'moisturized' refers to its ability to retain water molecules.

Transepidermal water loss

Our skin is made up of over 70 percent water – a number that sounds like generous hydration. However, the body is constantly losing water through transepidermal water loss, or TEWL, which refers to the evaporation of water from the surface of the skin.

This is a process that is naturally regulated by the body. However, it can be influenced by environmental and biological factors, skin care habits and diet. This also explains why dry skin and dehydration are such common skin problems.

Prevent water loss

Low humidity environments or excessive cleansing can result in dry, flaky, pigmented or tired skin, or cause uncomfortable feelings of tightness or itching.

If these symptoms are due to dehydration, we recommend a dual approach. Formulations rich in moisturizing ingredients (which attract water to the skin's surface) and emollient ingredients (which support barrier function and therefore help prevent moisture loss) can help soften the skin and restore its moisture levels. Drinking plenty of water every day complements this care routine. A diet rich in omega-3 fatty acids is also recommended to supply moisture from within. Foods such as avocados, nuts, flax seeds and oily fish such as mackerel, salmon and herring are suitable for this.