UPDATE: Fundamentally, there is no safe way to sunbathe, a tan is not protective, it is not healthy, irrespective of the natural vitamin D boost you get through exposing your sun to the skin and regardless of the feelgood factor of sunbathing.
The UK’s Health Research Forum, a pressure group opposing the blanket ban on sunbathing that other organisations are attempting to implement, has just published its second report – Sunlight, Vitamin D, & Health (Edited by Oliver Gillie).
The report covers a conference held at the House of Commons in November 2005 and endeavours to devour some of the claims made by sunscreen manufacturers and cancer charities about the nature of sunlight and its effects on our health. The main argument HRF makes is that safe sunbathing is good for you, and more to the point, not getting enough sun exposure is actually potentially very harmful. Of course, it does not suggest getting sunburn.
“Dermatologists always say that tanning is bad because sunlight damages DNA of skin cells and kills them,” Gillie told me, “The way they say it makes it seem quite scary. But it doesn’t surprise me that skin cells die in the process of protecting us against the sun – bowel cells die protecting us against food.”
He adds that this process of cell death is a normal cycle of cell multiplication and death in the skin that
speeds up when the skin is exposed to UV. “I contend that a tan is part of a normal process and not pathological as dermatologists have been telling us,” he adds, “And having a tan is definitely associated with protection against cancer e.g. prostate cancer, and there is evidence for other cancers too.”
With this in mind, the HRF has come up with a how to on sunbathing so that UV users and sunworshippers can glean all the benefits with none of the harm:
- Sunbathe safely – WITHOUT BURNING – every day if you can
- In the UK, midday* is the best time to sunbathe
- Start by sunbathing for 2-3 minutes, each side, gradually increase from day to day
- Don’t use sunblock or suntan cream, when doing so
- If you get hot or uncomfortable expose a different area or use suncream
- When abroad, reduce exposure
- Children benefit too, but need guidance
- A tan is natural and is generally associated with good health
Why midday? The sun is strongest in the middle of the day and so maximum vitamin D synthesis occurs in the shortest time. This is important especially in the UK climate where it’s often overcast and UV intensity can be low. More to the point, one’s lunch hour is a great time to get out of the workplace on a sunny day (unless you’re a gardener of course, in which case you may want to sit in darkened room to eat your sandwiches), and that can have psychosociological benefits too.
Gillie adds, “Gardening is very good – you need to get as much sun/vit D as you can to see you through the winter,” he told me, “My suggestion is to protect your face with a hat much of the time because the face is otherwise always exposed – but be sure to take your shirt off and wear shorts whenever it is hot – and avoid burning.”
The full report is available as a pdf (912kb) here. I raised the issue of sunshine safety and cancer prevention in a previous write-up – sunshine, but organisations such as Cancer Research UK and RAFT (the Restoration of Appearance and Function Trust) contend that sunlight is the major risk factor for skin cancer.
UPDATE: New York Times and others are reporting on research this week that suggests that some types of sunscreen may do more harm than good, especially if they give users a false sense of security about sun exposure. Other recent work suggests that in the laboratory, at least, UVB (ultraviolet-B rays; 315–280 nm) do more damage to the DNA of skin cells (and so putatively lead to melanomas) than UVA (ultraviolet-A; 400–315 nm, lower energy per photon). The difference between UVA and UVB is simply a matter of wavelength/frequency of the ultraviolet electromagnetic radiation. The longer the wavelength (shorter frequency), the lower the energy.