PREMATURE AGING

Despite all warnings to the contrary, come summer, the beaches are packed as we bare our bodies to get a tan. While a small amount of early-morning sun is good for you (15 minutes is sufficient to provide you with natural vitamin D, and occasional exposure is believed to improve psychological wellbeing), too much sun is dangerous. Besides the fact that sun dramatically ages your skin, it is also the cause of several kinds of skin cancer, including solar keratoses (wart-like growths) and malignant melanoma - and just one bout of harsh sunburn may be all it takes. Photo ageing - which can make up to around 85% of the overall appearance of ageing - is a slow process and only becomes visible after a few decades. And then it is too late to do anything about it.

Unfortunately, although people are now waking up to the dangers of overexposure and the horrors of skin cancer, only about half of the world's population takes adequate precautions to protect themselves from the sun. Sun safety should be a vital part of your life and one that you must instill in your children from an early age.

Wrinkles and other sun-related signs of premature ageing begin to form up to 10 years before they actually appear.

Your best ally against premature ageing is the daily use of a good sunscreen. The higher the SPF (Sun Protection Factor), the oilier the cream generally is. So if you are prone to breakouts stick to SPF 15 or lower or try a gel formula.


Photo ageing, a result of sun exposure. is a slow process. It may take several decades before it becomes fully noticeable. In fact, 90% of sun damage occurs by the age of 20, only becoming visible in your early thirties and onwards. The degree of photo ageing is mainly determined by your skin type and total lifetime sun exposure, and the degree of damage to different areas of the body is directly proportional to the amount of sunlight received (your hands and neckline for example, are more likely to have sun damage and age spots than your stomach).

Seriously sun-damaged skin has a thickened outer layer, making it feel day, rough and leathery. There are often darkly pigmented areas or whitish spots where levels of pigment are higher or lower than normal. Pores may be dilated and small blood vessels become more obvious, sometimes forming broken or spider-like veins, and the skin may be mottled red or inflamed. Within the dermis, the elastic fibres increase in quantity and thickness, manifesting as deep, fixed wrinkles and less pliable skin.

THE SCIENCE OF SUNBURN
The sun energy that reaches the Earth can be divided into three kinds of light: infrared and visible light, and ultraviolet radiation (UVR). UVR, in turn, consists of three different wavelengths: ultraviolet A, B and C.

• Ultraviolet C is the shortest wavelength and potentially the most damaging. DNA and proteins absorb UVC due to their molecular structure. Fortunately for us, UVC is mostly absorbed in the atmosphere by ozone layer. However, the current 'thinning' of this layer has increased the amounts that reach our planet, especially in the Southern Hemisphere.
• UVB is the most potent wavelength as it can penetrate into the epidermis where it affects the DNA and can create lipid peroxides, precursors of free radicals. It is believed to generate most of the photo damage to skin. UVB is the wavelength responsible for sunburn, and is at its most dangerous in the middle of a summer day, when transmitted through a blue sky. Less UVB is transmitted in the early mornings and late evenings; when the sun is lowest in the sky.
• UVA is about 1 000 times less damaging to the skin than UVB, but it is far from harmless. UVA tays are longer than UVB rays, and 90% of the sunlight reaching the earth is made up of UVA rays. They are the 'ageing' rays, which penetrate deeper into the skin (the dermis) and are responsible for the damage to your collagen and elastin, and causing freckles, blotchiness and pigmentation problems. While UVB peaks at high noon in summer, UVA is fairly constant throughout the day and year and can penetrate cloud cover, tinted glass and clothing relatively easily. UVA also causes immune suppression, resulting in increased susceptibility to skin infections and even skin cancer.

HOW SUNLIGHT PENETRATES THE SKIN

SUNBURN VS SUNTAN
There is no such thing as a safe tan. A suntan is actually the body's defence mechanism against too strong sunlight and the visible evidence of damage to the skin. Sunlight stimulates the skin to increase melanin production. As the melanin supply is activated, it moves up towards the surface of the skin where it helps prevent burning and reduces the penetration of the sun's rays. The side effect is skin of that golden colour that sun worshippers crave. Although dark-skinned people have more melanin in their skin and thus have a higher level of natural protection, they still need to use a sunscreen to avoid skin damage.

Sunburn, on the other hand, can be equated to 'cooking' your skin. If you do not apply sunscreen, or accidentally fall asleep in the sun, the surface blood vessels dilate (hence the redness), and an inflammatory response is induced to fight the damage,often causing blisters in the process. The redness occurs tow to eight hours after severe sun exposure and blistering can occur after 12 to 24 hours. A frightening fact is that our skin 'remembers' this burn, and the DNA may not repair perfectly. These 'errors' in DNA can lead to skin cancer years later. So when you make your way to the coast for your next summer holiday, remember that although a tan fades quickly, your skin carries a permanent memory of the damage.

Overexposure to the sun at an early age will result in premature wrinkling between the ages of 25 and 40. The dangerous rays are not just from the sun's light - they are also reflected off water an the earth.

PROTECTING YOUR SKIN
The time it takes for unprotected skin to turn red in the sun is known as the MED (minimal erythema dose). Your skin type determines your MED. Very fair skin, for example, will have a MED of about six minutes; olive toned skin can tolerate about 10 to 12 minutes; and black skin usually has a MED of 18 to 20 minutes. SPF (Sun Protection Factor) is a standardized measure that indicates how much additional time above your MED you can spend in the sun without getting burned. For example, if you can usually spend 10 minutes in the sun before burning, an SPF15 sunscreen will multiply that time by fifteen (10 minutes x 15 = 150 minutes of 'sun time').

Note that a person with fair skin can spend far less time in the sun than someone with darker skin, even if they both apply the same level of SPF. Once your time is up, you should ideally get out of the sun. Reapplying sunscreen only means that you will 'cook' more slowly, a bit like cooking your Sunday roast in the oven - once it is done you are simply crisping it! You should, however, always reapply sunscreen after swimming, perspiring and drying yourself off. The key is to use enough sunscreen (one to two ounces) for an even and full coverage. Double application is also important: apply the first layer 20 to 30 minutes before you go to the beach, and apply another layer as your 'coat of armour' when you get into the sun.