Mechanisms of skin ageing and how to prevent and manage the premature ageing of skin
The eternal truth is that time goes only in one direction and we are all too familiar with the process of ageing.
As young individuals we all enjoy smooth and supple skin, that with the passage of time starts showing signs of ageing - fine lines at the eye corners, deepening of expression lines and appearance of wrinkles, pigmented spots, loss of elasticity, broken capillaries etc.
These visible changes are a result of the ageing of the skin and are influenced by two major processes.
First, the natural ageing process also known as intrinsic ageing, that is genetically determined and irreversible. Genetics determine the rate at which skin ages by impacting the skin durability, the hormonal mechanisms and the skin thickness.
Second, environmental factors such as cumulative sun exposure, air pollution, prolonged exposure to wind, cold, air-conditioning or poor treatment of the skin, stress or lifestyle habits as smoking can lead over time to a cumulative damage to the skin. These changes in the skin due to environmental factors are also known as extrinsic ageing and they usually appear in the areas of the body that are the most exposed to the elements - face, neck, decolletage and hands.
Solar radiation is the major factor causing the premature ageing of the skin. The ageing of the skin caused by the cumulative sun exposure is also called 'photoageing’. In particular, photoageing is demonstrated by the premature appearance of wrinkles, dryness, sallow complexion, age spots, loss of firmness and elasticity or visible capillaries.
And while we can’t stop the natural ageing process, we can learn how to manage and minimise signs of premature ageing caused by the exposure to the elements.
CHANGES IN THE SKIN DUE TO THE NATURAL AGEING PROCESS (INTRINSIC AGEING)
With the natural passage of time many changes occur in all areas of the body irrespective of their exposure to the sun. Skin loses its firmness and elasticity, wrinkles appear, the skin becomes thinner and more fragile and these are mainly due to:
1. Degeneration of the collagen fibres
Collagen fibres are collected together into bundles oriented in different ways to form a fibrous structure the main function of which is to support the internal structure of the skin. Changes in collagen due to the natural ageing process are characterised by the thickening of collagen fibres and clumped and disorganised collagen compared to the organised pattern of collagen seen in younger skin. These alterations of collagen in ageing skin lead to the formation of wrinkles.
2. Degeneration of elastin fibres
Elastin fibres form a loose mesh and their main function is to give the skin the elasticity and resiliency, i.e. the skin’s ability to return to its original state after stretching. In ageing skin the elastic fibres undergo changes that are characterised by the thickening and coiling of elastic fibres. This leads to loss of elasticity of the skin that in turn may account for much of the sagging of the skin often seen in elderly people.
3. Thinning of the skin
With ageing metabolism slows down and the cell renewal process becomes less efficient. The time needed for renewal of the outermost layer of the epidermis or stratum corneum is 20 days in young adults and approximately 50 days in older adults. The longer time needed for cell renewal leads to a slower replacement of stratum corneum and slower wound healing. This in turns results in the development of dead cells heaps onto the skin that renders its surface dull and rough in appearance. Skin is visibly thinner and more fragile.The fatty layer of the skin also becomes thinner. The loss of the fatty layer is more prominent in certain areas like the face, hands and calves.
4. Skin becomes dryer
With age, skin loses its ability to retain moisture and it becomes dryer. This is partly due to the gradual decline in the activity of sebaceous glands, especially apparent after menopause in women. Sebaceous glands produce the skin's natural oil known also as sebum that together with sweat form a lipid layer on top of the skin that serves as barrier preventing the loss of moisture from the skin and growth of bacteria. Therefore, a decrease in production of sebum will lead to dryer and more sensitive skin.
5. Skin complexion becomes sallow
With ageing blood circulation slows down and the number of blood and lymphatic vessels in the skin reduces. Therefore, nutrients and oxygen essential to the healthy appearance of the skin are not brought as quickly to the underlying tissues and respectively waste products and toxins are not removed properly. This results in the development of yellowish complexion and pallor that give the skin unhealthy looks.
CHANGES IN THE SKIN DUE TO THE PHOTOAGEING PROCESS (EXTRINSIC AGEING)
Exposure to the sun is the major environmental factor causing damage to the skin. Also, exposure to other environmental factors like cold, wind or ill treatment of the skin can cause cumulative damage to the skin over time. As mentioned above, the major reason in the wrinkle formation and loss of firmness is the degeneration of elastin and collagen fibers. These fibers degeneration occurs naturally and gradually in naturally ageing skin, but it is intensified by prolonged exposure to the sun. The changes in ageing skin due to environmental factors, especially sun exposure, differ in presentation from the skin changes due to the natural process of skin ageing. For example, in photoaging skin more cells are formed in the epidermis, which makes the skin thicken in irregular patterns. This is in stark contrast to the thinning of the epidermis due to the natural ageing process of the skin. In addition to this, photoaging skin is characterised by changes like appearance of uneven pigmentation, age spots, dilated blood vessels.
Changes in skin due to intrinsic ageing of the skin: Changes in skin due to photoageing:
Skin becomes thinner Skin becomes thicker in irregular patterns
Collagen and elastin fibres degenerate gradually Collagen and elastin fibers degenerate with accelerated pace
Skin becomes lighter due to the decreased production of melanin Appearance of uneven pigmentation - age spots
Skin becomes dryer Appearance of visible blood vessels
Photoaged skin is also characterised by the appearance of fine lines and wrinkles, deeper expression lines and sagging of the skin.
1. Premature appearance of fine lines and wrinkles due to sun damage
The cumulative sun exposure or the ultraviolet (UV) radiation can cause significant damage to the skin tissues and cells. The UVB (burning) rays have shorter wave length and high intensity and they cause sunburn and tanning of the skin by affecting the cells of the epidermis (the top layer of the skin). On the other side UVA (ageing) rays have longer wave length and they penetrate deeper into the dermis. Although UVA rays do not cause burning of the skin, they cause irreparable damage to the dermal structure that do not have the ability to continuously regenerate themselves as the epidermis does. UVA rays are responsible for the ageing of the skin and for the premature damage of the collagen and elastin fibres that leads to the skin losing its strength and elasticity, the appearance of fine lines and wrinkles and the deepening of the expression lines.
2. Appearance of pigmented spots as a result of cumulative sun exposure
Suntanning is the result of sun exposure and leads to the darkening of the skin. In fact, tanning is the natural skin mechanism to protect itself from the solar radiation, but usually is not enough to prevent skin damage. Special cells in the epidermis, called melanocytes, produce melanin, which is a pigment with dark colour that makes the skin darker in order to protect it from the sun. However, in fair-skinned people the quantity of melanin produced by the melanocytes is not enough to provide them with adequate levels of sun protection. Therefore, sun damage is more pronounced in fair-skinned people. In dark skinned people the quantity of the melanin produced is more and their skin’s natural sun protection mechanism is more efficient.
3. Sagging of the skin due to sun damage
The main damage to the skin due to the prolonged sun exposure is the deterioration of the quality of collagen and elastin fibres. The skin loses its elasticity and strength and this combined with the loss of subcutaneous fatty tissue due to chronological ageing may lead to skin loosening and wrinkles. The loose skin is further pulled down by gravity that leads to sagging skin.
4. Broken capillaries due to sun damage
In addition, cumulative exposure to the sun damages the delicate blood vessels of the skin and the supporting tissues.The blood vessels become more fragile, making them more prone to haemorrhages (bleeding) following relatively minor injury. Similarly, the capillaries of the face may enlarge and become visible. Visible capillaries that results from cumulative skin damage are usually in the form of little red lines lines that are visible under the skin.
5. Dry skin as a result of sun damage
Excessive exposure to the sun dries out the skin. When there is constant dryness of the skin over a prolonged period of time, the skin’s health and quality is affected.
MEASURES TO PREVENT PREMATURE AGEING OF THE SKIN
1. A healthy mental and emotional state
Stress and negative emotions do affect the skin. They trigger series of physiological reactions in the body that change the blood supply and oxygenation to the skin’s underlying tissues, irritate the nerves in the skin, increase inflammation. A prolonged state of stress affects the skin's health and cause damage to the skin. Also, expression lines due to anger, prolonged stress or depression can turn into permanent expression lines and wrinkles.
There is a relationship between a healthy mental and emotional state and healthy skin. Therefore, techniques and activities that bring stress levels down can result in better skin and fewer expression lines.
2. A healthy and balanced diet
A healthy balanced diet composed of all groups of foods, vitamins, minerals antioxidants and anti-inflammatory ingredients accompanied by maintaining steady weight is highly recommended in order to avoid the appearance of premature signs of ageing.
3. Good Sleep
Good sleep is essential for the health of the skin. Your skin repairs and recovers itself while you sleep and enough sleep - 7 to 9 hours - can ensure numerous benefits for your looks. Fewer sleep hours are likely to affect your appearance and in the long run, sleeplessness may cause cumulative damage to the skin looks.
While you sleep, skin makes new collagen that prevents the formation of wrinkles and skin sagging. Also, blood supply to the skin is boosted and nutrients and oxygen are delivered to the skin tissues while toxins are removed. During sleep the growth hormone that plays a significant role in maintaining the quality of tissues, including muscles and skin is secreted. Inappropriate sleep may hinder the secretion of growth hormone that, in any case, tends to decrease after 40 years.
4. Regular exercise
Regular exercise and increased activity has a pumping action on the blood vessels thus pushing blood to the heart which improves blood and lymphatic circulation that in turns brings more oxygen to the tissues and efficiently removes waste products and toxins. Regular exercise helps the skin to retain its healthy and radiant complexion.
5. Regular massage
The benefits of a facial massage are similar to these from regular exercise. They include increased blood supply to the skin tissues and underlying muscles thus increasing the inflow of nutrients and oxygen and stimulating collagen production, improved lymphatic circulation that facilitates the removal of waste products and toxins accumulated in the skin tissues and stimulating or relaxing effect on nerves that helps the release of stress.
In long term regular facial massage is one of the most powerful forms of anti-ageing therapy that ensures and maintains the health and youthfulness of the skin.
6. Use of broad spectrum sunscreens
The damage of the skin caused by cumulative sun exposure has been well documented. When walking out in the sun you should protect yourself by applying topically a broad-spectrum sunscreen. Broad-spectrum sunscreens contain ingredients that can absorb or block both UVA and UVB light. Broad spectrum sunscreens help to prevent sunburn, damage and premature ageing of the skin and skin cancer, including the appearance of coarse wrinkles, pigmented spots, dryness, loss of elasticity and broken capillaries. The use of hats and protective clothing when outdoors are also highly recommended. The use of sunglasses is also recommended as they will prevent the damage caused by UV radiation to the eyes and the inevitable response of squinting that helps the appearance of crow’s feet.
7. Exfoliate with AHA products
Alpha-hydroxy acids (AHA) are compounds derived from dairy products (lactic acid), fruit (malic acid and citric acid) or sugar cane (glycolic acid). Regular application of topical treatments with AHA has demonstrated to reduce roughness of the skin and improve wrinkling and pigmented spots. It has also been documented that AHA-s lead to improvements in the thickness of the skin epidermis and collagen density. A new generation of AHA, called polyhydroxy acids appear to have similar benefits as well as anti-oxidant properties without the irritation effect common to AHA.
8. Use of products with retinoids
The regular application of products containing retinoic acid (retinoids resembles vitamin A in their chemical composition) improves, to a certain extent, the signs of photoageing and chronological skin ageing. Retinoic acid was originally intended for acne treatment. However, dermatologists observed its beneficial effect for treating signs of ageing when treating adult women with acne. These patients reported that their skin became somewhat smoother, and fine wrinkles flattened and nearly disappeared. Dark spots were lightened, and some completely dissolved.
We are familiar with free radical damage that occurs with oxidative stress caused by sun, environmental pollutants, and lifestyle habits such as cigarette smoking. Free radicals are molecules containing oxygen with one or more unpaired electrons which makes them very unstable and prone to react with other molecules. In order to become stable, free radicals are looking to steal one or more electrons from other molecules, which leads to chain of undesirable chemical reactions in the skin cells. These undesirable chemical reactions are also called oxidative stress and leave the skin cells damaged and unable to function properly.
Antioxidants are molecules that can give away unpaired electrons to free radicals thus stabilizing the free radicals and preventing skin cells damage and degeneration.
The use of antioxidants in any anti-ageing skin care regimen is essential in order to combat and prevent further damage to the skin. For many years, vitamins have been used to combat free radical damage. Enzymes are also efficient free radical scavengers; however, they depend on the presence of a healthy cellular environment and certain trace minerals to synthesise them.
There is growing evidence of the synergy that exists in using combinations of antioxidants along with sunscreens.
10. Facial expressions
Facial muscles are attached directly to the skin. With every facial expression muscles on the face contract that also causes folding of the skin. In young individuals when muscles are relaxed facial expressions from the skin disappear as the skin returns to its original form due to its well functioning elastic fibers. However, when muscles contract under tissue with degenerated collagen and elastic fibers, fine expression lines appear as the skin is not able to return to its original form. With time these fine expression lines become deeper, more pronounced and permanent. Every individual has unique facial expressions and usually expressive habits are unconscious and remain throughout life. Facial expressions affect the formation of wrinkles. For example crow’s feet form when squinting or forehead horizontal lines are formed due to the repeated raising of eyebrows.