{"id":2437,"date":"2011-04-21T16:28:12","date_gmt":"2011-04-21T23:28:12","guid":{"rendered":"http:\/\/www.functionalps.com\/blog\/?p=2437"},"modified":"2011-04-21T16:28:50","modified_gmt":"2011-04-21T23:28:50","slug":"sunlight-information-skin-cancers-and-vitamin-d","status":"publish","type":"post","link":"https:\/\/www.functionalps.com\/blog\/2011\/04\/21\/sunlight-information-skin-cancers-and-vitamin-d\/","title":{"rendered":"Sunlight Information: Skin Cancers and Vitamin D"},"content":{"rendered":"
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Sunlight Information: Skin Cancers and Vitamin D by Barry Groves<\/strong><\/p>\n<\/div>\n

Introduction<\/h3>\n

For the past several decades the numbers of skin cancers, and particularly the deadly one, malignant melanoma, have risen dramatically among Caucasian populations throughout the world. In the USA melanoma is the seventh most commonly diagnosed cancer with a rate of 14.2 cases per 100,000 population, (1)<\/sup><\/a> while in 1987 Queensland, Australia, had 55.8 cases per 100,000, the world’s highest rate. (2)<\/sup><\/a> The incidence of the various types of skin cancer in the general British population has been increasing at an annual rate of two to eight percent over the past 2 decades. (3)<\/sup><\/a> The contributory factors seem to be a light-skinned, northern European population living in areas of high ambient sunlight, and the incidence of the disease is seasonal, with more cases reported in summer than winter. Yet several clinical and epidemiological aspects of cutaneous melanoma seem anomalous because they contrast with other sunlight-associated skin cancers. For example, persons with the greatest risk of melanoma are not those with the greatest cumulative solar exposure; the anatomic areas that receive the most solar exposure are not preferentially affected; and not all light-skinned people suffer the same – albino Africans who have no pigmentation, are more likely to get sunburn and a number of other skin complaints as a result of exposure to the sun, but they don’t get melanomas. (4)<\/sup><\/a><\/p>\n

In the 1960s I lived with my family in Singapore, just 1.5 degrees from the Equator. I have blond hair, fair skin and blue eyes. It is a combination not believed to be suited to the harsh sun of the tropics. Nevertheless, I regularly went on the beach, to the swimming pool or sailing on the South China Sea with little or nothing on, in the heat of the midday sun. I don’t go brown, the best I can manage by way of a tan is a dark golden colour. I remember, in an effort to deepen my tan, I would lie out for hours with the sun to one side of me and its reflection in a mirror of cooking foil on the other to increase my exposure. Like everyone else in the ex-patriot Singapore community, I didn’t give skin cancer a thought in those days; the phrase ‘malignant melanoma’ was unheard of.<\/p>\n

I didn’t use a sunscreen. They too were unavailable. If we used anything at all, which most of the time we did not, it was usually a well-shaken mixture of coconut oil and vinegar. This was a concoction used at the time by naturists. We smelt like a fish and chip shop, but we didn’t get burnt in the years we lived there.<\/p>\n

Today, it seems, all that has changed. Why? What has changed in the last forty years?<\/p>\n

Skin cancers<\/h3>\n

There are three major forms of skin cancer:<\/p>\n