Dr Michael Ardern-Jones (FRCP, DPhil, Senior lecturer and consultant dermatologist) explains...
Why should we look after our skin?
The skin is often considered to be Mother Nature’s equivalent of the cellophane wrap. Medics have long described the skin as a window on the health of the body. It seems as though for many years both doctors and the general population have largely ignored the well being of the skin itself. Increasing understanding of the nature of health and disease in the skin coupled with recent scientific findings have demonstrated that the more we understand the skin the more it appears that the skin is anything but a cellophane wrap.
The skin is now recognised to be an organ in its own right, just as important to the functioning of the body as the kidneys and the lungs. Without skin, survival is impossible. With damaged skin, for example as induced from birth by some genetic conditions, a great deal of suffering may be encountered and sometimes life may be unsustainable. As you might naturally alter your lifestyle to look after your heart, so looking after the largest organ in the body (your skin) makes sense. To better understand the ways in which the skin can be helped it is important to understand its functioning. Broadly speaking the skin serves three main functions: protection from the outside world, regulation of the environment inside the body and communication to others. Protection from the outside world is largely dependant upon the cells that make up the skin which form a barrier to the environmental factors that can harm us. It has recently been demonstrated that a ‘leaky’ barrier is an important cause of eczema. Although communication is frequently overlooked in medical textbooks, clearly the role of the skin in conveying all kinds of messages from love to anger cannot be overestimated.
What happens to skin with age?
As you get older, so the skin also gets older. Similar to the way joints tend to deteriorate with age, the cells making up the skin work less efficiently. The analogy can be extended: we all recognise that osteoarthritis joint damage is more common in long distance runners; similarly we recognise that cutaneous ageing effects are more rapid in those people who give their skin a hard time. When the skin ages one of the most noticeable changes is a reduction in elasticity due to reduced effects of a protein called elastin. This means that the skin no longer snaps back after being pinched up. As a consequence the skin starts to hang rather than stick. The other noticeable effect is that the fibroblast cells make less collagen which results in the skin getting a little thinner. When the skin gets thinner and less elastic, the result is that fine wrinkling starts to develop. The other prominent change with ageing skin is due to increased water loss through the skin because of a more permeable barrier. This results in dryness which becomes initially visible as a loss of sheen and lustre to the skin. The combination of fine wrinkling and dryness provide the most recognised changes in ageing skin.
It is not unreasonable to ask why might the skin age in this way and what can be done about it. Ageing is a natural process and despite our efforts, cannot yet be stopped! However, there are some things that we can stop doing to inhibit the natural ageing process and there are some things we can start doing to convince the skin that it should age more slowly. The dominant factor that enhances skin ageing is ultraviolet light (sun). The sun penetrates deep into our skin and is good not only because it makes us feel warm but also because it helps the skin make vitamin D for the whole body. Unfortunately, as with anything you can have too much of a good thing. It is mainly the pigment in our skin which protects us from the effects of the sun. Over many thousands of years we have evolved to get the right balance between enough sun for vitamin D versus damage to our skin. This has resulted in the differences in skin colour seen in different populations across the world. It is often remarked that people with dark skin age well. This is probably a reflection of the protective role that melanin plays against sun damage. For fair skinned individuals this protection can be replicated by the use of sunscreens or cosmetics containing sunscreens which have been extensively studied and demonstrated to protect against skin ageing. Further enhancement of the damage caused by sunlight is due to cigarette smoking.
How does the menopause affect skin ageing?
At the same time as wrinkles naturally arise, so the body provides a double whammy to females: the menopause. On average women reach the menopause at age 52, but 1 in a 100 women will start this early before the age of 40. During the menopause the ovaries decrease production of the female sex hormone oestrogen. Numerous studies have demonstrated that skin ageing correlates with reduced levels of oestrogens in women and that oestrogens are able to reverse the natural reduction in collagen synthesis in skin cells. Whilst it is reasonably clear that prescription of hormone replacement therapy solely for the treatment of skin ageing is not recommended, recent work has shown that two weeks application of oestrogen to the skin as a cream increases collagen production (Rittié et al., Archives of Dermatology, 2008). This study demonstrated the need for combined UV protection and topical oestrogen to see the maximum benefit. Emerging evidence suggests that flavanoids (including phytoeostrogens) may have a role to play in both enhancing collagen synthesis as well as sun protection through their anti-oxidant properties (Widyarini et al., Proceedings of the National Academy of Sciences USA, 2006). One of the advantages of treating skin problems is that treatments can be applied directly as a cream so limiting the chance of any side effects due to absorption into the bloodstream. For this reason, it is likely that novel treatments such as those described here will be best employed as a cream rather than as a tablet.
After many years it seems that as we are now, better than ever, coming to understand the changes in our skin by interpretation of findings from cutting edge science. These can be used to identify strategies that will not only benefit skin diseases such as skin cancer, but also limit the undesirable changes associated with skin ageing. In 50 years time maybe things will be simpler and we’ll just be able to order a new cellophane wrap on the internet.
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