Why is skin so important?
The skin is the largest (in terms of surface area and weight) and most visible organ of the human body. This dynamic organ undergoes numerous changes with time. It is crucial for our overall health and well-being and is renewed every 28 days.
Skin performs numerous functions (protection, regulation of body temperature, sensory function, production of vitamin D, etc.) and is more than just the packaging of the body. It also plays an important psychological/social role. Beautiful, firm skin is regarded as a sign of youth and boosts our self-confidence.
What does our skin look like on the inside?
Skin consists of 3 main layers, each having its own specific properties and functions.
Epidermis (outer skin):
The upper skin layer functions like a shield, protecting the body from outside attacks. In good health, it is responsible for supple, elastic, hydrated and firm skin. The epidermis consists of 5 layers that continually renew the skin in a constant process of new skin cells replacing the old and dying cells. In addition, the epidermis contains pigment cells (melanocytes) that help determine the colour of the skin and offer protection against UV rays.
Dermis (true skin):
This is the layer beneath the epidermis that mainly consists of connective tissue. It is responsible for the firmness of skin. Fibroblasts are the most important cells in the dermis. They are crucial for firm, supple, elastic skin. These specialized cells function as factories of collagen (for firmness), elastin (for elasticity) and hyaluronic acid (for hydration).
Hypodermis (subcutaneous connective tissue or subcutis):
The deepest layer of the skin that consists mainly of fat and connective tissue. It functions as a cushion, storing energy in the form of fat and forming the connecting layer with underlying tissues.
How does skin change over time?
As we age, our skin changes. Skin ageing is a normal, natural phenomenon that starts already at the age of 25 to 30 years.
Skin ageing is caused by a combination of factors. Both internal factors (genes, biological age, ethnicity, skin type) and external factors (exposure to sunshine, smoking, pollution, stress, alcohol, unbalanced diet, hormonal imbalance) are in tandem responsible for structural skin ageing in the form of wrinkles and pigmentation spots.
Over the years, the essential supporting structure of skin starts to degrade. The natural production of collagen, hyaluronic acid and elastin declines with ageing (Fig X), causing the skin to lose its firmness, suppleness and hydration. In combination with external factors (exposure to sunshine, pollution, smoking, etc.), this makes skin thinner, flabbier, drier, more brittle, more pigmented and more vulnerable. Fine lines, crow's feet and (deep) wrinkles begin to appear and the young, firm, radiant skin gives way to 'more mature' skin.
Why are collagen, elastin and hyaluronic acid indispensable for youthful skin?
Collagen is a protein that naturally occurs in humans and animals. It forms a fibrous network that provides structure to body tissues. It gives the skin its strength, flexibility and resilience. Not only skin, but also blood vessels, bones, tendons, ligaments, cartilage, nails, hair and teeth contain collagen. This body protein represents around one-third of all the protein in the body and accounts for 70% of the network that gives firmness to our skin. There are different types of collagen, the most important ones for the body being type I and II.
Fibroblasts are specialized cells in the dermis that constantly produce collagen. From the age of 25 to 35, collagen production slows down and its degradation accelerates. The elastic skin fibres start losing their structure and resilience. Skin becomes thinner and drier, and loses its volume, firmness and radiance. Fine lines, wrinkles and other signs of skin ageing gradually emerge.
Aged skin therefore exhibits a damaged, fragmented and less well-organized collagen network in the dermis. This will reduce not only collagen synthesis, but also elastin and hyaluronic acid production.
Elastin is a protein that plays a key role in blood vessel walls and long tissue, but also in the skin. It makes skin supple and elastic, allowing the skin to return to its original shape after stretching. With age, the fibroblasts produce less elastin so that also the elasticity of the skin declines, promoting the appearance of fine lines and wrinkles.
Hyaluronic acid is a substance that occurs naturally in the body, not only in skin, but also in eyes, joints, gums, connective tissue… It is the champion of hydration. Hyaluronic acid molecules bind up to 1,000 times their weight in water and are capable of ensuring optimal skin hydration. During the ageing process, the quantity of hyaluronic acid decreases, resulting in dry, dull, saggy skin. With its powerful hydrating properties, hyaluronic acid helps delay and repair the effects of ageing.
Scientific studies have shown that the intake of collagen can stimulate the synthesis of new collagen fibres by the fibroblasts. Collagen-boosting anti-ageing products may therefore be valuable allies in maintaining healthy, firm and young-looking skin.