Science On How To Hydrate Skin
Here’s how to hydrate skin from a scientific point of view! You may think that hydrating the skin is just slapping a cream on the skin and boom – you’re done! But it’s so much more complex than that! In fact, DMK International Founder Danné Montague-King told us, “Creams don’t moisturize, they deliver.”.
Deliver what? Where is it going? How does it all work?
How To Hydrate Skin – The 2 Keys
In order to understand how to hydrate skin, you have to examine how the skin is designed and how it functions. The skin is an incredible organ and designed to hydrate itself and to keep that hydration locked in, selecting what it will allow to enter, ensuring it keeps bacteria and other such non-desireables out. It does all of this in the stratum corneum in and around the corneocytes.
The 2 Keys To Maintaining Hydrated Skin
The skin has something called the Natural Moisturizing Factor and the Lipid Matrix.
“The corneocyte ‘bricks’ contain intracellular humectants (natural moisturizing factors/NMFs) that are essential for barrier function, skin hydration, and skin cell turnover. The lipid ‘mortar’ is arranged into lamella layers consisting of cholesterol, free fatty acids, ceramides, and sterol/wax esters. This lipid matrix is crucial for the prevention of transepidermal water loss (TEWL) .
For this reason, skin hydration is largely dependent on the presence of NMFs and the structure and composition of the lipid matrix.” ScienceBecomesHer.com
Science Becomes Her Explains Moisturizers by Explaining Barrier Funtion
“The Epidermis & Stratum Corneum Barrier Function
The skin is the largest organ of the human body and acts as our first line of defense against various environmental pollutants. It is responsible for preventing excess water loss from the body and is made up of three main layers – the epidermis, the dermis, and the subcutaneous layer (or hypodermis) .
The epidermis is the outermost layer of the skin and is responsible for its barrier function. It is made up of four layers – the basal layer, the spinous layer, the granular layer, and the stratum corneum (or cornified layer).
Epidermal skin cells (keratinocytes) begin their life attached to a basal membrane in the basal layer. Here they multiply rapidly before detaching from the membrane and moving outward through the spinous layer and the granular layer until they undergo cornification (a programmed cell death that transforms keratinocytes into flatter corneocytes) and are eventually shed by the stratum corneum .
As the skin cells migrate through the layers of the epidermis, they release lipids into the spaces between them. Because of this, the stratum corneum is often said to have a ‘brick-and-mortar’ structure, where the corneocytes are the bricks and the lipids are the mortar-like substance that holds them together. Together, the corneocytes and lipids form a water-repellent barrier .
The corneocyte ‘bricks’ contain intracellular humectants (natural moisturizing factors/NMFs) that are essential for barrier function, skin hydration, and skin cell turnover. The lipid ‘mortar’ is arranged into lamella layers consisting of cholesterol, free fatty acids, ceramides, and sterol/wax esters. This lipid matrix is crucial for the prevention of transepidermal water loss (TEWL) .
For this reason, skin hydration is largely dependent on the presence of NMFs and the structure and composition of the lipid matrix.
NMFs represent 5-30% of the stratum corneum and consist of amino acids and their derivatives (e.g. lactic acid, urea, and sugars), while the lipid matrix is made up of ceramides (45-50% – by dry weight), cholesterol (25%), and free fatty acids (10-15%) “.
Mimic The Lipid Matrix
In the same time that we were researching this article we came across an Instagram post from Roccoco Botanicals that discussed balancing and maintaining the skin barrier.
“It comes down to the fact that our skin requires the following three things in balance to maintain our skin barrier. 1️⃣ Fatty Acids, 2️⃣ Cholesterol, 3️⃣ Ceramides.” Roccoco Botanicals Instagram Post.
We found this interesting, however, in an attempt to relate it to products that can be used on the skin we looked back to Science Becomes Her.
Science Becomes Her Explains Emollient Rich Moisturizers
“How Do Moisturisers Work?
It was originally believed that moisturizers worked by preventing TEWL through occlusion (i.e. creating a layer on the skin that traps water inside). However, after the discovery that lipids (particularly ceramides) play a vital role in skin hydration , it is now known that there are multiple mechanisms at play.
These mechanisms include:
- Repairing the skin’s barrier
- Increasing water content
- Reducing TEWL
- Restoring the lipid barriers ability to attract, hold, and redistribute water .
There are three main groups of moisturizers – Emollients, Occlusives, and Humectants.
Emollients soften, smoothen, and condition skin by filling in the gaps between cells/skin flakes with droplets of oil. If applied heavily, they can also act as occlusive agents. Emollients are mainly oils and lipids, particularly lipids that are naturally present in the stratum corneum . This can help replenish depleted lipids and is particularly effective when ceramides, cholesterols, and fatty acids are combined together .
In fact, applying only one or two of these lipids to dehydrated skin may actually delay skin barrier recovery . Specifically, they need to be combined in a ratio of between 1:1:1 to 3:1:1 (ceramides: cholesterol: fatty acids) for maximum skin hydration and barrier repair . One study found that a topical cream that combined all three lipids was able to improve skin hydration within 30minutes of application .
Other popular emollients include aloe vera, shea butter, linoleic acid, oleic acid, stearic acid, and cetyl alcohol. In addition, some oils, such as mineral oil and jojoba oil, work as both emollients and occlusives.”
How To Hydrate Skin That is Dehydrated
It’s clear that emollient moisturizers contain oils and lipids that are similar to those in the skin and can help to replenish liquids. It’s clear that using an emollient moisturizer with all 3 lipids (fatty acids, ceramides and cholestoral) will improve the skin’s hydration.