Des Spence is a general practitioner based in Glasgow, Scotland, UK, who writes a weekly column in the British Medical Journal. Although I’ve never met Des, I like him a lot. I like how he writes and what he writes, almost always. He’s never afraid, it seems, to buck the trend and express a view that is out of keeping with conventional ‘wisdom’. Earlier this year I wrote a post based on one of his columns which took the practice of cardiology to task. You can read the blog post here.
This week’s focus for Dr Spence was sunlight, and the growing clamour that children should be protected from it [1]. In this column he makes the point that sunshine is healthy, and that the reason some of us have pale skin is because evolution selected for this, as it was an advantage in terms of making sufficient vitamin D (from sunlight) for health in areas where sunlight is in generally short supply.
Then he casts a critical eye over melanoma and its relationship with sunlight. He makes the point that melanoma most commonly occurs in places that are less sun exposed. He also alludes to the fact that melanoma is more common in indoor workers than outdoor workers. He doesn’t mention this, but I think it’s also worth bearing in mind that most melanomas do not occur in typically sun-exposed parts of the body. Dr Spence does point out, though, that there is scant evidence that sun protection reduces the risk of melanoma, and none at all that it saves lives.
Dr Spence also makes the point that the rising incidence of melanoma is almost certainly due to ‘overdiagnosis’. Increased awareness of melanoma by the medical profession and members of the public have led to increased diagnosis of lesions which were not destined to pose a threat to health in the long term.
Finally, Dr Spence draws our attention to increasing issues regarding vitamin D deficiency, and the fact that sunscreens block vitamin D production. As Dr Spence points out, low vitamin D levels can cause bone disease and is linked with enhanced risk of cardiovascular disease and several forms of cancer.
Here’s Dr Spence’s last paragraph in full:
“I pale at the potential consequences of the current sun policy on the long term health of our children. We should trust evolution: the current policy is counterintuitive, and bad medicine.”
He’s right, too.
References:
1. Spence D. Bad medicine: melanoma. BMJ 2011;343:d5477
