The Sun – By Dr Vernon Ching

July is UV Awareness Month

Despite the weather being cold one is tempted to stay outdoors for long stretches to enjoy the fresh South African air, and not worry about using sunblock. Here in South Africa, protection from the sun is necessary all year round, for several reasons.

THE SUN AND PREMATURE AGING

Frequent exposure to sunlight accelerates skin ageing. Ironically, we are pursuing the ‘Fountain of Youth’ more than ever, yet still doing exactly what makes the skin age the fastest – exposing it to the sun.

A sun-kissed radiance has come to symbolise ‘the good life’, a life of leisure, youth and healthy living depicted by spending hours in the sun – on the beach, at the pool, on the tennis court or just working in the garden.

Yet outdoor living is ‘frying’ the life out of our skins. Sun exposure causes up to 80% of the changes we characterise as “ageing” in our skins: freckles, thinning or thickening of the skin, blotchy pigmentation, enlarged or broken blood vessels, loss of firmness, wrinkles, crow’s feet, rough texture and “sun” spots.

People with fair skins who have a history of sun exposure develop more signs of photoaging than those with darker skins where photoaging signs are usually limited to fine wrinkles and a mottled complexion.

Photoaging occurs over a period of years. With repeated exposure to the sun, the skin loses the ability to repair itself and the damage increases. Sun-weakened skin loses its elasticity and becomes loose, wrinkled and leathery much earlier due to unprotected exposure to sunlight.

While it may seem that the signs of photo ageing appear overnight, they lie invisible beneath the surface of the skin for years. UV photography using the Vectra system from Canfield enables us to see the damage accumulating beneath the surface of the skin years before the signs of photoaging appear.

Most of us get half our lifetime’s exposure to the sun before we’ve reached the age of 18. The reason we don’t notice it is that much of the damage to our skin will only appear years later.

DOES A SAFE SUNTAN EXIST?

Many health organisations have stated that even if we think a suntan looks healthy, it’s not, and that the sun exposure needed to get a tan increases your chances of getting skin cancer which is the most common form of cancer in the United States and leads to more than 1 million new cases of cancer each year.

Research has shown that a suntan is the body’s best effort to protect itself from the known carcinogenic effects of ultraviolet (UV) light, the invisible portion of the light spectrum that penetrates the skin and changes DNA.

A suntan occurs when UV light strikes cells in the skin called melanocytes. These cells produce the brownish-black pigment called melanin, which darkens the skin. Although a tan doesn’t cause cancer, it’s a sign of the skin’s response to the harmful stress of UV radiation that almost certainly does.

WHAT SPF SUNBLOCK SHOULD I USE?

Short of avoiding the sun, sunscreen is the best tool you can use to protect yourself from skin cancer but should be the last step you take. UV rays are responsible for most of the symptoms of sunburn: redness, erythema and blistering. UVA is worse than UVB as UVA rays may cause skin ageing and increase the risk of skin cancer.

Recently the FDA has brought out preliminary recommendations that there are only two products — zinc oxide and titanium dioxide — which are considered GRASE (generally recognised as safe and effective). PABA and trolamine salicylate, would not be considered GRASE as are many other common ingredients in sunblocks for which there is currently insufficient data.

Active ingredients of sun blocks vary from brand to brand and can be separated into chemical versus physical agents.

Sunblock protects your skin by absorbing and reflecting UVA and UVB radiation. All sunblocks have a Sun Protection Factor (SPF) rating. This rating indicates how long a sunscreen remains active on the skin. A person can roughly work out how long their sunblock will be active by multiplying the SPF factor by how long it takes for him or her to suffer a burn without sunscreen.

For instance, if you usually sunburn in 10 minutes without wearing sunscreen, a sunscreen with an SPF of 15 will protect you for 150 minutes (10 minutes multiplied by the SPF of 15). Although sunscreen use helps minimise sun damage, no sunscreen completely blocks all wavelengths of UV light.

The American Association of Dermatology (AAD) recommends that a “broad spectrum sunblock” with an SPF of at least 30 should be applied daily to all sun-exposed areas to protect against both ultraviolet A (UVA) and ultraviolet B (UVB) rays and then reapplied every two hours.

The majority of chemical agents work in the UVB region and only a few chemicals block the UVA region. Properly applied, an SPF 50 sunscreen blocks 98 per cent of the type of sunlight that causes reddening and sunburn, called UVB rays, and an SPF 100 sunscreen blocks 99 per cent.

However, many people think these higher-SPF products mean that individuals wearing sunscreens can spend more time in the sun. However, this is not the case.

New studies have shown that in addition to UVB and UVA, Infrared Radiation (IR-A) and the High Energy part of visible light (HEV) can also cause skin damage.

SHUN THE SUN

For now, your best bet is to avoid excessive UV light exposure – especially if you’re blonde or redheaded and don’t tan well.

The best way to prevent skin ageing and other damaging effects from the sun is to stay out of it, especially between 10 am and 4 pm, when the sun’s rays are strongest.

If you can’t, apply sunscreen with an SPF of 50+ freely and use about two to three tablespoons for your whole body (don’t forget the lips and ears), wear a hat and sunglasses, and cover up with clothing when outdoors.

SUNBLOCKS WORK ONLY IF THEY ARE USED EFFECTIVELY

All sunscreens should be applied 15-20 minutes before sun exposure to allow a protective film to develop and should be reapplied every two hours or after going in the water or sweating. If you’re particularly active or will be sweating or swimming, you may want to find a sunscreen that is sweat-resistant or water-resistant.

Also avoid deliberate tanning, including the use of indoor tanning devices.

If you notice changes to your skin such as a mole changing appearance, a new growth, or a sore that won’t heal, see a doctor right away.

For more information, contact: Dr Vernon Ching Plastic and Cosmetic Surgeon Waterfall City Hospital, Midrand. Tel: 011 304 7888.