A recent press release from the American Acadamy of Dermatology (AAD) claimed that sunshine exposure was not necessary to obtain sufficient vitamin D and should certainly not be deliberately sought. Dr Gilcrest, a professor of dermatology said "The cause-and-effect link between UV exposure and the great majority of skin cancers is uncontested." This widely held view features strongly in campaigns being run by the AAD in preparation for the coming US summer.
A recent article from news-medical.net was headlined "Summer sun safety – research reveals significant link to melanoma" and opened with the statement that: "Fifty years of medical studies show that sun exposure is a primary component in the development of melanoma, the most serious and deadly type of skin cancer, report leading dermatologists in the April 2006 issue of Dermatologic Surgery."
The article then quotes Elisabeth K. Shim, M.D., an Associate Clinical Professor of Dermatology at Keck USC Medical School of Medicine in Los Angeles, CA. as saying: "Though genetics may play a role in the development of some melanomas, there’s overwhelming evidence that shows sun exposure adversely affects patients both with and without genetic predisposition to melanoma."
However, the article then went on to state: "It’s not clear what pattern of sun exposure causes melanoma or whether it’s short, intense intermittent or cumulative. Furthermore, it’s not clear if ultraviolet B (UVB), ultraviolet A (UVA) rays, or both are responsible for causing melanoma." to which Dr Shim merely added: "Regardless, the sun acts as an initiating and promoting agent in causing melanoma, and causes immunosuppression."
It seems to me that this significantly weakens the position adopted by dermatologists in demonizing the Sun. Their position is far too sweeping given the inadequacy of their knowledge and far too strong given what they acknowledge they simply don’t know. Given Dr Shim’s statement of what dermatologists don’t know, it is high time to ask just what exactly do dermatologists know?
The article concluded: "With summer quickly approaching, it’s necessary to protect yourself by using sunscreen and sun protective measures to prevent melanoma, and other skin cancers, despite current controversy." I agree that protection should be used where sensitivity is high or strength of risk is great. Certainly one should never permit exposure sufficient to cause sunburn. However, regular direct exposure to sunshine confers significant health benefits.
When we consider how long we have had the Sun and then study the patterns and trends in melanoma rates it seems obvious that one or more extraneous or intervening variables are implicated in developing skin cancers and it raises doubts about dermatologists’ claimed significance of exposure to sunshine. As one potentially modifiable risk factor it does seem reasonable to advise caution with sunshine exposure but it is time to play a different tune, one that details better informed approaches.
