Comprendre les effets de la gravité sur l’état de la peau
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The loss of skin elasticity and firmness associated with aging is a natural process resulting from various factors. Earth's gravity undoubtedly plays a significant role in this phenomenon, but among the causes of skin sagging, there are also several natural mechanisms that contribute to how the skin reacts over time.
A better understanding of these physiological factors can help us establish a suitable skincare routine to combat premature skin sagging and appear more youthful.
The biological mechanisms at play
Skin sagging, also known as 'skin ptosis,' refers to the sagging or loosening of the skin, often due to aging, collagen and elastin loss, or genetic factors. It can affect various parts of the body, including the face, breasts, arms, and abdomen. The treatment for skin ptosis may vary depending on its severity and the affected area. Treatment options can include cosmetic surgery, such as a facelift, as well as non-surgical treatments like dermal fillers or laser treatments to improve skin texture. A functional cosmetic formulation incorporating ingredients targeting various mechanisms of skin ptosis is also a beneficial non-invasive solution, both as a treatment and as a preventive measure.
The primary biological mechanisms involved in skin ptosis are:
- Decrease in the production of structural skin proteins
- The decrease in subcutaneous fat
- The weakening of muscles
- Dehydration
1. Decrease in the production of structural skin proteins
Collagen and elastin are essential proteins that give the skin its firmness and elasticity. With age, the production of these proteins decreases, leading to a loss of skin firmness.
Elastin's key role in resisting gravity and skin sagging
Elastin in the skin functions similarly to a spring, providing elasticity that allows the skin to maintain its firmness and structure, even when subjected to movements and temporary deformations such as facial expressions or other temporary changes. It helps prevent the formation of wrinkles and fine lines by preserving the skin's structure and firmness. When we are young, our skin contains a significant amount of elastin, contributing to firm, supple, and elastic skin. However, as time passes and with aging, elastin production decreases, which can lead to a loss of elasticity and contribute to the signs of skin aging.
Elastin is also involved in the skin's healing process, aiding in restoring the skin's normal structure after an injury by promoting tissue regeneration.
Tropoelastin: an essential precursor to elastin
Tropoelastin is produced by fibroblasts, which are cells responsible for synthesizing it as a precursor to elastin
Tropoelastin is assembled within skin cells before being delivered to the extracellular matrix. At this stage, tropoelastin is not yet in its functional elastin form. It must undergo a conversion process first. This process involves the binding of tropoelastin molecules together, forming elastin. Eventually, the newly formed elastin molecules group together to form elastic fibers in the skin's connective tissue, especially in the dermis.
Interaction with Collagen: Elastin interacts with collagen, particularly with Type I collagen, which is the most abundant type of collagen in the skin. Together, elastin and collagen contribute to maintaining the structure, firmness, and elasticity of the skin.
Collagen: well-deserved international acclaim
Collagen forms fibrils, which are thin structural fibers, much like the framework of a building. Just as the framework gives structure and strength to a building, collagen provides resilience and firmness to the skin. These fibrils interweave to create a three-dimensional network in the dermis, the skin's deep layer.
Skin cells, such as fibroblasts, are integrated into the collagen structure. These cells actively produce collagen and contribute to maintaining its structure.
Collagen can act as a mediator in cellular communication. It interacts with other proteins and molecules to regulate various cellular processes, including collagen synthesis itself.
Dies beinhaltet die Selbstregulierung: Kollagen wird kontinuierlich in der Haut erneuert. Zellen produzieren neue Kollagenmoleküle, um diejenigen zu ersetzen, die im Laufe der Zeit abgebaut werden.
In the skin, there are several types of collagen:
- The most abundant one: type I collagen
It represents approximately 80% to 90% of the total collagen. It provides the skin with strength, firmness, and stability. It is present in the dermis, the deep layer of the skin - Type I collagen's counterpart: type III collagen
It also contributes to the skin's flexibility, helping to support cellular structures. It is often found alongside Type I collagen in the dermis. - Collagens supporting and anchoring the dermal-epidermal junction: type IV and type VII collagens
They are crucial for the formation of the basement membrane, a structure that separates the epidermis from the dermis. - The ‘collagen booster': type V collagen
Type V collagen associates with Type I Collagen to form fibrils and is involved in regulating collagen growth and arrangement in the dermis. Therefore, it is found in the dermis.
Each type of collagen contributes specifically to the skin's structure and function. They interact complexly to ensure the stability, resilience, and flexibility of the skin. The distribution and relative quantity of each type of collagen vary in different layers of the skin, allowing for structured and functional organization.
2. the decrease in subcutaneous fat
Fat plays a role in maintaining the fullness and youthfulness of the skin. Mature skin can lose subcutaneous fat, which can contribute to the appearance of sagging skin.
The explanations for this phenomenon are multifaceted, but understanding them can help create 'anti-gravity' or 'plumping' formulas that target these various causes. For example, one can mention:
- Alteration of metabolism with age
This phenomenon can affect how the body stores and utilizes fats. A decrease in this metabolism can contribute to the loss of subcutaneous fat. - Reduced sebum production
With age and in response to various hormonal changes related to menopause, despite the number of sebaceous glands remaining the same, their size and secretion (sebum) tend to decrease. This results in a reduction in the production of surface lipids. The skin may then appear thinner and less hydrated. - Fat distribution
Of particular interest to specialists in aesthetic medicine is the modification of fat distribution. Fat distribution in the body and even in the face changes with age. Some areas may experience fat loss, while others may accumulate more fat. This redistribution can influence the appearance of the skin, with areas referred to as 'heavy' tending to weigh down the face, and others referred to as 'hollow' potentially contributing to a tired and wrinkled appearance.
The simultaneous decrease in collagen, elastin, and subcutaneous fat production
The loss of structural proteins (collagen and elastin) can lead to a decrease in the skin's structural support, including the subcutaneous adipose tissue. As subcutaneous fat production is already declining, if it cannot be retained, the effect will be even more visible in terms of tissue sagging.
3. weakening of muscles
The underlying muscles also support the skin's structure. With age, these muscles can weaken, contributing to skin sagging. Facial yoga becomes particularly relevant in addressing this phenomenon.
4. Cutaneous dehydration
Mature skin often tends to be drier, which can accentuate the appearance of wrinkles and fine lines, contributing to skin that appears more affected by gravity.
In conclusion, by formulating a skincare routine combining specific ingredients that work on the “gravity effect”, mature skin will enhance its ability to fight against gravity, leading to less skin sagging and a more youthful appearance.
Editor: Dr. Baruchet, Doctor of Biology