Skin aging is inevitable. There are many complex physiological factors that contribute to aging skin.
Let’s start with a little anatomy.
The main functions of the skin are feeling of touch, pressure, and pain; maintenance of fluid and electrolyte balance; temperature management (sweating, shivering, etc.); and protection of internal organs from the environment.
There are three main layers of skin.
The outermost layer is called the epidermis. This layer contains skin cells, melanocytes (pigment producing cells), proteins (keratin) that maintain the skin barrier, and Langerhans cells (immune cells that help fight infections).
The middle layer is called the dermis. This is the layer that contains skin cells, blood vessels, nerves, hair follicles, and sebaceous glands. The dermis is the layer that provides blood supply and nutrients to the epidermis. This layer contains collagen, the protein that provides structure to the skin. Think of this as the scaffolding of your skin. Collagen fibers also create the infrastructure for hyaluronic acid (hydration). This layer also contains elastin, the protein that provides elasticity, or bounce back, of tissue.
The deepest layer is called the subcutaneous layer. This layer contains sweat glands, blood vessels, fat, and some hair follicles.
Now, let’s talk about what happens as we age.
With increasing age, the epidermis thins. The number of melanocytes (pigment producers) decreases, but the size of remaining melanocytes increases. Therefore, aging skin is thinner, and formation of sunspots (lentigos) appears. The number of keratinocytes decreases, making the skin more fragile and less elastic.
Collagen production slows as we age which means thinner, drier skin leading to increased wrinkle formation. Think of this as a loss of scaffolding so there is less structure for the skin to sit on. This process starts at age 30!
Elastin production slows as we age which means the bounce back of tissue decreases. Think of a rubber band that has been stretched too many times. It stretches out and loses its ability to snap back to its original size.
Starting at age 30-35, the natural aging process causes loss of about ten percent of subcutaneous fat. This process continues and we lose approximately five to ten percent of facial fat volume every five to ten years.
How do environmental factors affect this process?
UV exposure is responsible for up to eighty percent of visible signs of skin aging. Exposure to the sun will increase the skin’s production of melanin (this is why we get tan in the sun). Over time, some areas of the skin can develop hyper-proliferation of melanin, which will result in a sunspot.
UV exposure can cause collagen break down at a higher rate than normal aging. This is because UV rays penetrate through the epidermis into the dermis and increase the formation of reactive oxygen species (ROS). ROS damage collagen and elastin and this damage leads to wrinkled, leathered skin.
Why does all this matter?
The skin is a complex structure that not only functions to protect our organs and help our bodies maintain homeostasis, but also functions as a component of external beauty and health.
Preventing skin aging is much easier that treating damaged skin. This means a daily routine personalized to your own skin needs and goals, in office treatments for maintenance, and SUNSCREEN, SUNSCREEN, SUNSCREEN!