Healthy skin needs moisture
If the skin becomes thirsty, this has unpleasant consequences. At first, the skin simply feels dry, tense or itchy. In the stratum corneum, the horny layer, water-soluble enzymes are left stranded and regulate the protective cuticle layer. This is how rough, scaly patches form. The skin loses elasticity and becomes cracked or shows hairline fissures that make it look older. Spoiler alert: oil alone is not enough. This only has a moisturepreserving effect, but not a moisturedonating effect.
☝️ Note: Dry skin needs a combination of moisture AND fat.
This is how the skin retains moisture
You can't just pour water into the skin at will. It doesn't flow into invisible tanks somewhere below the surface from which it can draw forever. The skin needs it in the horny layer and that's where it stores it. Here is a mix of active ingredients known as Natural Moisturizing Factor (NMF) . It soaks up water like a bath sponge.
But even such a sponge dries out again over time and shrivels up. To ensure that this does not happen to your skin, it also secures this store with the skin barrier. This is intended to prevent transepidermal water loss (TEWL), i.e. the evaporation of water from the skin.
💡 The NMF determines how well the skin is able to absorb moisture. The TEWL indicates how quickly the moisture is released again.
In short: Your skin is well moisturized when it has enough of its own moisturizing factors (NMF) to bind water and an intact skin barrier to prevent it from losing it1. But what exactly do these two components consist of and how can you optimally support your dry skin here? Let's dig a little deeper here!
The moisture content of the stratum corneum: the role of the NMF
The composition of the natural moisturizing factor
The Natural Moisturizing Factor is not a single substance, but a mixture of water-soluble, powerful humectants that the body produces or absorbs from food. These include amino acids, salts, glycerin, urea and hyaluron1. Healthy cells in the outer layer of skin contain around 20 to 30% of NMF by dry weight (i.e. excluding water).
The role of the NMF
The NMF substances act like small water magnets and bind moisture in the horny layer. If they are not fully utilized, they draw in additional humidity to fill up their stores.In principle, the system regulates itself. This is important because a well-hydrated horny layer:
- Keeps skin plump and elastic.
- Creates an optimal working environment for water-loving enzymes responsible for the skin's natural desquamation.
- Maintains the skin's acid mantle that protects against infection, dehydration and external aggressions.
What is interfering with the NMF?
On the one hand there is very dry ambient air. It does not provide fresh water to the NMF and ensures that the water that is present evaporates more quickly. In addition, the skin may be lacking in substances that are part of the NMF. For example, the amino acid content decreases as we get older. Mature skin therefore has a lower storage capacity than young ones.
How to support your skin's NMF
Treat her to a moisturizer with hygroscopic ingredients - i.e. water magnets - such as hyaluronic acid, urea and Glycerol. With this you not only hydrate, but practically carry out a memory expansion.
Even a balanced diet should never be underestimated for skin health and for our NMF. Your body cannot produce essential amino acids such as leucine or lysine itself, and it also absorbs salts from food.