Russell and Carol - hayle and hearty

Kira Cochrane asks "why can't we give up the tan?" (Going for the burn, G2, 7 July). The answer is simple: we are not convinced that the alleged harm outweighs the obvious benefits, and we dislike the bullying, fear-mongering campaign against sun exposure.

Skin cancer statistics are used to scare, not educate. Almost all of the 84,000 skin "cancers" that appear each year are in fact benign: they don't spread or kill; their cancerous name is a historical misnomer. Of course, sun exposure increases facial wrinkling, as does smoking, but the black ace in the fear game is melanoma, because the real thing is vicious.

As the article tells us, Cancer Research UK say the incidence of malignant melanoma has "quadrupled in Britain in the last 30 years". But if this were so we would have seen coffin-loads of consequences by now. We haven't, and in a recently published large UK study (British Journal of Dermatology, 2009), I and my colleagues showed that the reason mortality has not increased with incidence is that the tumours reported are actually benign; they are not true malignant melanomas. Our explanation of the phoney melanoma epidemic is "diagnostic drift which classifies benign lesions as … melanoma", a misdiagnosis "driven by defensive medicine, an unsurprising response to its commercialisation".

The recategorisation by the International Agency for Research on Cancer that Cochrane quotes, which gives sunbeds "the same high risk … as cigarettes and asbestos", is absurd. The field is an unreliable mess of conflicting conclusions, and the claim of a special risk for younger people, which the article repeats, is now denied. But critically, since we now know incidence is invalidated by classifying benign disease as malignant, until diagnosis is improved only studies of melanoma mortality are acceptable; and the few that have been done show that melanoma mortality actually decreases after UV exposure!

The poor relationship of melanoma to cumulative UV dose had solarphobics running for cover in the idea the article quotes, that a one-off sunburn "could develop into a melanoma". But that doesn't happen: unlike the benign tumours that really are caused by UV, melanomas do not predominate in sun-exposed skin. There are commonsense reasons to avoid sunburn, and for use of sunscreens – but not, as Cochrane implies, to prevent melanoma, for which they have been shown to be ineffective.

Cochrane wonders why "we still associate tanned skin with good health", but there are many good reasons. Although the medical uses that gained Niels Ryberg Finsen a Nobel prize have long past, there are newer uses in photo-chemotherapy, dermatology and psychiatry.

Self-image is measurably increased by a tan, and we will learn much from understanding the mechanism of this wellbeing. UV initiates the synthesis of vitamin D, essential for our bones, and sunscreen promotion has led to problems. It also has a profound effect on our immune function. Strangely, the bastard science of descriptive epidemiology that masterminded the melanoma myth now claims that UV lowers the incidence of many internal cancers and melanoma, thereby outweighing any harmful effects.

Plants and animals owe their existence to the sun, and it is hardly surprising that we've learned to adapt and use it. That's why we can't give up our tan, and more importantly why we shouldn't try.

Related Links

• Response: Don't let the phoney melanoma scare keep you out of the sun | Comment is free | The Guardian
• bmj.com Rapid Responses for Shuster, 337 (jul22_2) 764

Links from Article Text

• Don't let the phoney melanoma scare keep you out of the sun
• Going for the burn
• cancer
• "quadrupled in Britain in the last 30 years"
• British Journal of Dermatology, 2009
• gained Niels Ryberg Finsen a Nobel prize