As man-made climate change progresses, so does the cost to human health, not least the proliferation of skin cancers resulting from thinning of Earth’s protective ozone layer. Already, malignant melanoma is the most rapidly increasing form of cancer in the world. And, while the ozone layer is on the mend, thanks to the Montreal Protocol that banned CFCs in 1987, it will be 50-100 years before normal ozone levels are restored.

There are three main types of skin cancer: basal cell (which accounts for 90% of all cases), squamous cell, and melanoma, named for its origin in the melanin cells that give us our skin colour. (A suspected fourth type, Kaposi’s sarcoma – the most common cancer in AIDS patients – may actually be a form of herpes rather than cancer.)

Basal cell, a small, waxy or pearly lesion with a dimpled center and red blood vessels at the perimeter (most commonly occurring on the face), is the least dangerous because it almost never spreads (metastasizes) elsewhere in the body. Squamous tumours form a dry, wart-like lump, sometimes red and scaly. In 2-6% of cases, this cancer will metastasize, and can be fatal.

Malignant melanoma, on the other hand, almost invariably metastasizes if left untreated, and once let loose in the bloodstream or lymph system, it can be extremely difficult to stop. Its appearance is distinctive: a red, brown or even bluish blotch under the skin. It also occurs in moles and is best spotted by following the ABCDE rule: Asymmetry, Border irregularity, Colour alteration, Diameter enlargement, and Elevation. Any or all of these symptoms mean only one thing: get it checked – now.

Although cancer is always scary, skin cancers are normally easily and safely removed with minor day surgery, given early detection. Better still, skin cancer is largely preventable. While the most important precaution is avoiding over-exposure to sunlight, the risk can be even further reduced by maintaining a strong immune system.

For that you need a diet of whole foods, high in fruits and vegetables, and low in sugar and saturated fats; exercise regularly and, most important, if you are prone to stress, do something to combat it. Qi gong, yoga, mediation and breathing exercises can all be very effective.

You could further buttress your defenses with vitamins A, C and E, grapeseed extract, green tea, curcumin (tumeric) and omega 3 oils such as flax and fish. These are all powerful antioxidants, antidotes to free radicals, which are believed to be contributing factors to cancer.

Finally, you might ask, if sunlight is the villain in the skin cancer story, why not just stay covered up or keep yourself smeared with sunblock? Because sunlight is essential, not just for the formation of vitamin D in the skin, but also, it seems, as a key ally in the prevention of cancer. Just within the past month, a major scientific study linked several types of dangerous cancers in women with a shortage of vitamin D.

So, to sunbath or not? Moderation, as always, should be your watchword. And remember, heavy duty sunblocks are not the whole answer. Anything over SPF 8 stops vitamin D production in the skin.

©Dr. Gordon, 2007.