Most people don’t realise it but sun protection is actually the best anti-wrinkle treatment you can get.
Unlike Victorian times when women valued porcelain-white skin and generally shunned the sun, women these days prefer a “healthy tan” and would lie for hours under the sun. However, there is nothing healthy about a tan; because tanning comes with sun damage and not only will your skin age faster but you will also be at a higher risk of developing skin cancers.
The dangers of sun-damage are often not appreciated because the consequences (wrinkles and skin cancers) do not appear until 10 – 20 years later. In Australia, where the beach culture has been particularly strong, the death rate from melanoma (cancerous mole) has increased from less than 1.0 per 100,000 between 1931-34 in both men and women to 5.0 and 2.4 per 100,000 in men and women respectively between 1990-94. Changing attitudes about tanning is more urgent now because we’re getting much more sunlight because of the depletion of the earth’s ozone layer.
Tip
If you want to see how much damage the sun has caused to your skin, just look at the difference between the skin on the inside of the upper arm, which is shaded from the sun, and the exposed skin on the outer part of the forearm. Just see for yourself how much better your skin would be had you protected your skin from the sun from an early age.
SOLAR RADIATION
The figure below shows the different types of radiation emitted by the sun. Only the portion known as the terrestrial solar spectrum reaches the earth’s surface. The earth’s ozone layer absorbs ultraviolet (UV) rays below 330nm and almost all rays below 295nm. UV is composed of UV-A, UV-B and UV-C. UV-C, which has a wavelength between 200 – 290 nm and absorbed by the ozone layer. In other words, only visible light (the colours of the rainbow with a wavelength of 400 – 750nm), some UV-A (320 – 400nm) and UV-B (290 – 320nm) reaches the earth’s surface. More UV-B and UV-A rays are reaching the earth now because of the depletion of the ozone layer and this is one of the possible reasons for the increase in the number of cases of skin cancers. Depletion of the ozone layer has resulted in a large hole over the Antarctic and this is believed to have been caused primarily by the use of chlorofluorocarbons (CFCs), hence the move to ban their use.
UV-B are short wavelength (290 – 320 nm) rays that penetrate the top layer of the skin and cause sunburn. In the past, it was thought that one could protect the skin against sun-damage by merely screening out UV-B. This was a mistaken view. UV-A takes longer to produce a burn but penetrates more deeply into the dermis by virtue of its longer wavelength (320 – 400nm) and is now thought to be mainly responsible for the damage to collagen and elastin fibres that keep the skin firm and elastic. UV-B is thought to be responsible for causing sunburn, basal cell and squamous cell cancers. UV-A causes tanning and acts with UV-B to promote the development of skin cancers, including malignant melanoma. Being of a longer wavelength, UV-A can also penetrate the ozone layer better than UVB and can penetrate glass which UV-B cannot. The amount of UV-B varies, being maximum from 10am – 2pm (11 – 3pm during daylight saving hours) whereas the amount of UV-A is virtually constant. This means that we are actually exposed to more UV-A than UV-B on a day to day basis, inside buildings and in the car. So always protect the exposed skin with sunscreens effective against UV-A as well as UV-B.
Another surprising observation is that even incidental exposure to the sun is harmful. Dr Nicholas Lowe and his colleagues in the US irradiated the backs of volunteers with UV rays of a dose that was equivalent to what most of us get by walking to and from the car and driving a car. After 3 months, they found changes in the melanocytes, the blood vessels in the skin and also the elastin fibres that indicate sun-damage.
SKIN PHOTOTYPES
The degree of protection our skin has against the sun is directly related to the amount of melanin pigment in the skin.
Fitzpatrick skin phototypes (modified)
| Skin type | Reaction to sun-exposure | Examples |
| Type 1 | Always burns, never tans | Light-eyed, fair-skinned Northern Europeans |
| Type 2 | Always burns, sometimes tans | Fair-skinned Europeans. |
| Type 3 | Sometimes burns, always tans | Mediterranean origin eg. Spaniards, Italians and Greeks |
| Type 4 | Never burns, always tans | Hispanics and Asians. |
| Type 5 | Dark pigmented Asian skin. | Hispanics and Asians. |
| Type 6 | Black skin. | Darkly pigmented Africans and Southern Indians. |
The Fitzpatrick skin phototype classification is also useful for determining suitability for resurfacing treatments such as chemical peels, dermabrasion and laser resurfacing. Phototypes I – II are good for all these treatments but darker skin types, especially phototypes III and IV are more prone to develop temporary post-inflammatory hyperpigmentation (increased pigmentation compared to the surrounding skin. Forget about using the skin phototype as a guide to determine the SPF of a sunscreen to use so as to get a tan because tanned skin is simply sun-damaged skin. Tanning has to be avoided at all cost. There is no such thing as a healthy tan!
Whilst darker skin types are more protected against sunburns and skin cancers because they have more melanin (which acts as a natural sunscreen), they suffer from another type of sun-damage – melasma or pigmentation. Hence, they should also use sunscreens, especially when they live in the tropics.
You can determine your Fitzpatrick Skin Phototype by accessing our online calculator:
Fitzpatrick skin type calculator
Classification of photoageing
| Grade of photoageing | Signs | Patient characteristics |
| Type I “no wrinkles” Early photoageing | Mild pigmentary changes No solar keratoses (precancers) Minimal wrinkles | Patient age: twenties and thirties Minimal or no makeup |
| Type II “wrinkles in motion” Early to moderate photoageing | Early solar lentigines visible Solar keratoses can be felt but are not very visible Parallel smile lines beginning to appear | Patient age: late thirties or forties Usually wears some foundation |
| Type III “wrinkles at rest” Advanced photoageing | Obvious dyschromias (uneven pigmentation), telangiectasias Visible solar keratoses Wrinkles even at rest | Patient age: fifties or older Always wears heavy foundation |
| Type IV “only wrinkles” Severe photoageing | Yellow-grey colour of the skin Prior skin malignancies Wrinkled throughout, no normal skin | Patient age: sixties or seventies Can’t wear makeup “cakes & cracks” |
(Modified from Glogan R G: Chemical Peel Symposium. Amer Acad Dermatol Atlanta, Dec 4, 1990):
Asians and other races with skin phototypes IV and above have more melanin pigment shield the dermis (deeper skin) and protect them from wrinkles. However, their melanocytes bear the brunt of the damage from UV rays leading to melasma, age spots (solar lentigines) and idiopathic guttate hypomelanosis (reverse of age spots) and unevenness of pigment tone. Wrinkles seem to occur at a later age than their caucasian counterparts.
Mechanism of photoageing
Ultraviolet radiation causes the realease of reactive oxygen species (ROS), which damages cells, causing the signs of photoageing. Ultraviolet B (UVB) has high energy but shorter wavelength and penetrates the upper layer of the skin called the epidermis causing DNA damage there. Ultraviolet A (UVA) has lower energy but able to penetrate the deeper part of the skin called the dermis causing damage to the elastic tissue, collagen, blood vessels and immune cells.
PROTECT YOUR SKIN AGAINST SUN-DAMAGE
Slip, Slop, Slap – the Aussie way to healthier cancer-free skin.
Learn helpful tips for better healthier looking skin from Dr Lim Kah Beng’s book, Steps to Skin Beauty. It is out of print but available for loan from National Library Board.