Skin hydration is a more important subject than just having “water in the skin”. Based on the work of a meta-analysis published in the summer of 2022 in The Cureus Journal of Medical Science , I would like to give you the keys to understanding the different factors that affect skin hydration. And also highlight my products, since they are in line with what science says.
Once upon a time… skin!
As the largest organ in the body, the skin plays many essential roles, such as protecting the body from pathogens, regulating body temperature, maintaining cellular fluids, synthesizing vitamin D, and detecting stimuli.
There are 3 layers in what we commonly call the skin: the epidermis, the dermis and the hypodermis.
As you can see, the top of the epidermis is made up of the hydrolipidic film and the stratum corneum. Together they form the skin barrier , that is, the body's first line of defense, which works to form an effective barrier between the body's internal and external environments. Indeed, the three main functions of the skin barrier are to limit passive water loss, to limit the absorption of chemicals and to prevent infections.
But how is this stratum corneum formed? To simplify, let's say that skin cells are “born” and proliferate deep down, then gradually rise to the surface, depending on their stage of aging. Because each stage of aging corresponds to a specific function in the organization of our skin. When they reach the stratum corneum, their function is to maintain an effective epidermal barrier against excessive loss of water, ions and proteins.
Role of certain skin cells and the mason metaphor
A certain type of skin cells, called corneocytes, make up a large part of the stratum corneum. Yes: corneocytes = horny cells = cells present in the stratum corneum. When you touch your skin, these are the cells you feel are your fingers. They help maintain trans-epidermal water loss from the body at normal values.
Trans-epidermal loss? It is the process by which water escapes from our skin (sweating, evaporation, etc.). We don't realize it, but this phenomenon does exist!
Back to our corneocytes: to do their job properly, they are arranged in a “brick and mortar” pattern , like a brick wall. Corneocytes are the bricks, while the mortar is mainly made up of a natural fatty substance, ceramides. By nature, these corneocytes have water binding and retention properties allowing them to absorb three times their weight in water.
But we have other natural assets produced by the body to retain our water, such as:
- Glycerol , which absorbs moisture from the air and helps form the skin barrier
- Or hyaluronic acid , which helps maintain the structural integrity and barrier function of the skin due to its water retention properties
- Or even keratinocytes , another type of skin cell, which plays a regulatory role in the synthesis of intercellular lipids. Intercellular lipids did I say? But yes, remember: our famous mortar! Without this mortar, no cohesion. And have you ever seen a solid, impermeable wall that retains water and heat, even though it has no cohesion? Well it's the same for the skin.
There you go, you now have, in a very simplified way, the fundamentals on the subject of “skin hydration”. And obviously, given that there are many players involved in ensuring good hydration of our skin, there are necessarily many disruptive agents which will negatively affect our good hydration.
Come on, let me take you on a quick tour of the main factors.
Environmental factors affecting skin hydration
The main environmental factors contributing to decreased skin hydration are UV exposure , low temperatures , and low humidity .
The effects of UV on the skin barrier include the loss of cellular cohesion and mechanical integrity on intracellular components of the stratum corneum, such as intracellular lipids (hello mortar!).
Seasonal climate also impacts skin hydration. A study aimed at understanding the influence of different seasons on the composition of stratum corneum lipids reported that stratum corneum lipid levels decreased in winter compared to spring and summer.
Nutritional Factors Affecting Skin Hydration
Proper nutrition and topical skin care are essential to help maintain skin hydration and elasticity. Until now, research into the effects of diet and skin hydration has mainly focused on vitamin C, calcium and polyunsaturated fatty acids.
Ceramides (mortar again?!) play an essential role in modulating water retention within the stratum corneum and pathologies leading to a reduction in ceramide content can lead to excessive water loss.
Aging as a factor in skin hydration
Age-related reductions in skin hydration have been reported, but the mechanisms responsible are not completely understood.
Nevertheless, one study found that all major lipid species, particularly ceramides, were significantly reduced in the stratum corneum with age. This would suggest a decline in skin barrier function with age. I'll remind you that we're talking about our favorite mortar, or have you seen it? 😊
The impacts of clinical conditions on skin hydration
Atopic dermatitis
Atopic dermatitis is a chronic, relapsing skin disease characterized by an unpleasant sensation that leads to the need to scratch, inflammation and dysfunction of the skin barrier leading to increased trans-epidermal water loss.
The full causes of atopic dermatitis are unclear, but dysfunction of the epidermal barrier and dysregulation of the immune system contribute. And among the factors contributing to skin barrier abnormalities, we find our mortar, with a decrease in lipid levels (among many other factors).
Psoriasis
Psoriasis is an inflammatory disease. Clinical features of psoriasis include dry skin and erythematous patches with thick scales with raised patches with a whitish accumulation of dead skin. Psoriasis is associated with increased transepidermal water loss and decreased water content of the stratum corneum.
And Hodyge in all this?
First of all, congratulations if you are at this stage of reading, the subjects covered are not necessarily simple.
You will surely have understood that well-hydrated skin is due in particular to low trans-epidermal water loss. For that it is necessary :
- Good organization of skin cells
- Effective intercellular cohesion (come on, let me insult you by mentioning our friend the mortar once again 😊)
In all our products, we use alkaline ionized water with recognized moisturizing properties.
In fact, from 30 minutes after application, trans-epidermal loss is reduced by 10%. This observation is verified at 21 days , with on average a significant reduction in trans-epidermal water loss of 14% on average (result verified on 100% of the 22 subjects in the study).
Another study on the alkaline ionized water we use showed that our alkaline ionized water:
- Improves skin integrity and strengthens the protective barrier function of the epidermis
- Improves the expression of enzymes involved in the synthesis of ceramides in keratinocytes, which have a protective function in the skin (for a good mortar)
Concretely, on the subject of skin hydration, we provide a natural response that takes into account the physiological needs of the human body. Natural response because our water is made up of 99.7 water molecules and 0.3% mineral salts; we take physiological needs into account because we do not provide temporary solutions by external additions of molecules, proteins, lipids, etc.
We help the body to regain its state of homeostasis , that is to say the natural regulation of the body to maintain constant the biological parameters of the human body in the face of changes in the external environment.
In short, at Hodygé, we want to take care of you , with the natural rules of your body.
Well I don't know about you, but I'm going to go and pour myself a glass of water, it will do some good for my skin and body hydration 😉
Source of meta-analysis:
“Physiological, Pathological, and Circadian Factors Impacting Skin Hydration” published August 4, 2022
Jose V. Camilion, Siya Khanna, Sheela Anasseri, Coral Laney, Harvey N. Mayrovitz
Photo: Mrjn Photography