Why oils are a myth for moisturizing
We've all read it countless times: «XY oil moisturizes and hydrates». The problem: From a scientific point of view, this is not only wrong, but quite outrageous.
Because the fact is: Pure oils are completely water-free. They are even hydrophobic - i.e. water-repellent. It goes without saying that oils can therefore not moisturize skin (and hair!). Nevertheless, they play an important role in the moisture balance of our skin. Sounds like a contradiction? We clear up the misunderstanding.
The important difference between moisturizing & retaining moisture
Facial oil actually ensures well-moisturized skin. But not by moisturizing. But by protecting the skin from excessive moisture loss . And it works like this: Oils support the functions of a healthy skin protection barrier by supplying the skin with important lipids. These, in turn, are important for keeping water in the skin.
To understand this interplay, let's go back to our brick example from part 1 of our series Oils for the face.
You can imagine the structure of the horny layer of our skin similar to a brick wall that is held together and stabilized by mortar. Our skin cells are the bricks, the skin's own lipids are the mortar. This lipid matrix consists of about 60% ceramides and 20% each of cholesterol and fatty acids1.
If there are not enough lipids, the wall or Skin barrier brittle. The result: firstly, the skin becomes more susceptible to environmental stressors, secondly, moisture cannot be optimally retained in the skin and escapes to the outside more easily.
Because oils contain lipids, they can fill in the gaps between the "bricks" and thus reduce the transepidermal water loss (this means the water loss through the skin's surface) keep in check: The skin appears well moisturized and healthy.