Skin Aging

As the organ of our body that comes into direct contact with the environment surrounding us, the skin shows the clearest signs of ageing. This process already starts at the age of about 30 and results in changes to both the appearance and the functioning of the skin. Ageing processes are the result of internal and external factors. The internal factors are known as endogenous processes, biological ageing or “time ageing”, the external ones as exogenous processes or “environmental ageing”. The factor that plays the most important role in environmental ageing is sunlight, and in particular ultraviolet light. The exogenous ageing of the skin caused by light is also known as “photoageing”.

More than 90 % of the skin changes that we find cosmetically disagreeable are the result of excessive exposure to UV light over a long period of time. The effects of photoageing are especially visible on the areas of skin that are regularly exposed to light, such as the face, the backs of the hands and the outside of the forearms. The skin in these areas appears “older” than, for instance, on the inside of the upper arms, which even in old people only show a fraction of the natural time-related ageing of the skin.

The most visible signs of skin ageing are thinning of the skin, loss of elasticity and tautness, wrinkling and dryness, a yellowish discolouring, and a variety of skin changes – some of them pigmented – as well as a decline in hair and nail growth.

Normal skin ageing, i.e. the type not caused by exposure to light, is the result of a slowdown and reduction in cell renewal, hormonal changes and genetic factors. The normal ageing processes include a thinning of the skin through a reduction in the thickness of the dermis, though less so of the epidermis. In the dermis, the number of connective tissue cells decreases. Also the number of melanocytes (pigment-producing cells) and Langerhans’ cells (immune cells) in the epidermis declines. There is also a marked reduction in the responsiveness of the blood vessels in the skin, i.e. for purposes of heat regulation, as well as in the production of sweat, sebum and vitamin D. This leads to a change in the protective barrier, the defensive responses and the healing processes of the skin. A visible indication for the slowdown in cell renewal and replacement is, for example, the fact that wounds take longer to heal.

Quite apart from the exposure to light, a number of harmless growths tend to occur on normally ageing skin. These include fibromas (fibre-like growths on the skin, especially on the neck and under the armpits), and small angiomas (i.e. the formation of new blood vessels, which are usually bright pink or bluish-red in colour and are harmless). Also enlarged sebaceous glands may occur (hyperplasia of the sebaceous glands). Another frequent phenomenon which people find disagreeable are flat, brownish spots of hyperpigmentation in the light-exposed areas of the face, the backs of the hands and the outside of the forearms. Seborrhoeic keratoses (brownish wart-like growths on the skin, which are sharply delineated and may be flat or raised with a cauliflower-like appearance) also tend to increasingly occur in the second half of our lives. Changes of this kind can appear on anybody’s skin, irrespective of exposure to light, and cannot be prevented.

However, this is not the case with the skin changes caused by exposure to sunlight. These can be prevented, or at least significantly reduced, by using appropriate sunscreens and limiting our exposure to the sun (“skin and sun”). Besides wrinkling, a typical result of light-induced damage to the skin are so-called solar keratoses (reddish to reddish-brown hornification disturbances of the skin). Also typical of light-damaged skin are irregular changes in pigmentation in the form of spots of hyper-pigmentation and small areas of depigmentation.

Enlargement of the small blood vessels (teleangiectases) can occur, especially on the cheeks and neck. Depending on the duration of light damage, the formation of fine or deeper wrinkles may occur prematurely, and in severe cases also comedones (blackheads/whiteheads) in yellowish, thickened, deeply furrowed skin – frequently above the cheek bones.

Cigarette smoking has been clearly shown to contribute to the formation of wrinkles, especially in the face. A typical “cigarette face” is characterised by pale, greyish, wrinkled skin with sunken facial features. In the case of heavy smokers, the formation of wrinkles is said to be five time more intense than in people of the same age who do not smoke. In terms of wrinkling formation, cigarette smoking is said to have the same negative effects as extreme exposure to the sun.

An undisputed consequence of damage to the skin from overexposure to sunlight over a long period of time are malignant skin tumours such as basal cell carcinomas, squamous cell carcinomas (epitheliomas), and malignant melanomas.

Preventive measures and lifestyle

In today’s society, health awareness and the desire to be physically attractive are becoming increasingly important. Many people therefore ask how the process of biological ageing can be slowed down and the process of environmental ageing prevented altogether. On the basis of current knowledge, ageing is largely the result of oxidative metabolic processes. Besides a healthy diet, maintaining a sensible body weight and taking physical exercise appropriate to one’s age, taking substances with anti-oxidant effects is recommended. Vitamin E, for example, has a photo-protective effect (i.e. it provides protection against light radiation) on the human body. Doses of between 400 and 800 mg daily should be taken for a period of several months, or even better for several years, or possibly even throughout one’s life. The anti-oxidant effect can be further reinforced by additionally taking ascorbic acid (vitamin C) and low doses of vitamin A.

As nicotine stimulates the oxidative metabolic processes, stopping smoking, or preferably not starting, can also be seen as a therapy against skin ageing. Attention should also be paid to using effective sun protection from the earliest age on. For most people, however, this advice comes too late. Nevertheless, it still makes sense to start using UVA and UVB filters straight away. Excessive infra-red radiation (heat) also promotes the process of skin ageing by causing damage to the connective tissues.

A positive attitude to life, a healthy lifestyle, a balanced diet and regular skin care all contribute to giving the skin a good appearance, and in this way to reinforcing people’s sense of self-esteem and well-being.

Care for ageing skin

As the skin ages, it becomes thinner, less able to retain moisture, and consequently drier. The skin care products used should therefore contain sufficient lipids and moisturising factors. The lipids help to reduce the moisture loss caused by thinning of the skin as they form a protective film on the skin’s surface and so support the skin barrier which becomes less effective with age. For the skin to remain supple, it needs a certain moisture content. For the horny layer (stratum corneum), for example, this is about 10 to 20 %. The water-binding substances are produced by the sweat and sebum of the skin. However, secretion by the sebaceous glands and sweat glands also declines with age, reducing the effectiveness of the hydrolipid mantle of the skin. Good moisture-retaining products are urea, lactic acid, glycerine and acidic mucopolysaccharides such as hyaluronic acid.

To avoid further drying of the skin, mild products should be used for cleansing (washing syndets or, as the simplest form, even baby soaps). Oil baths and shower additives can also combat skin dryness. Mineral oils are more effective than vegetable oils in forming a protective film. For skin care, lipid creams and water-in-oil emulsions should be used as the skin ages. Lipid components that correspond to the normal composition of the sebum, e.g. jojoba oil or shea butter, should be used for preference.

Sun protection

As already described in the section on “The sun and your skin”, using appropriate sun protection agents is the best means of preventing light ageing. The long latency period, sometimes of decades, before the first signs of premature sun-related skin ageing actually start to appear, is deceptive and means that people often fail to start using sun protection products in good time. However, constant and consistent use of such products is strongly advisable from babyhood on. The earlier people start protecting their skin, the less likely it will be to suffer light ageing when they get older. According to general scientific opinion, up to 80 % of all long-term damage to the skin is caused by the time people are aged 18.
This means they should start using sun protection agents with a UVA and UVB filter from as early an age as possible, and for preference products with a light protection factor of 20 or more. Only those products should be used that also absorb at least 90 % of the UVA radiation (“Australian standard”) in order to prevent ageing in the connective tissue of the dermis. A high UVA protection factor also helps to prevent most UV allergies.