The dangers and benefits of sun exposure are significant and complicated.
On one hand sunshine includes ultraviolet light, or UV, which is able to penetrate the skin’s surface and interact with the melanocyte cells there. If this damage is not repaired by the body, it can lead to the development of melanoma.
So for a long time the pervading message from public health bodies is to avoid harmful UV radiation by staying out of the sun and applying sunscreen.
However, the studies show a different relationship between the type of sun exposure and melanoma. Intermittent exposure, mostly associated with sunburn has been shown to cause melanoma. But studies show those who work outside and are exposed to the sunshine all the time have no increased risk.
So what is going on here? Firstly it is important to say that we don’t know for sure. Yet.
One of the answers there is growing evidence for is that Vitamin D may have a role to play. And this is where it gets contentious.
The same UV wavelengths that causes damage to the melanocytes, helps to produce Vitamin D. We need Vitamin D for a whole range of things and the vast majority of what we get is from exposure to the sun.
And increasingly there is evidence that higher levels of Vitamin D may reduce the severity of melanoma.
So it seems like a good point to recap what we’ve covered.
- Sunlight = UV exposure
- UV exposure = mutations to melanocytes which if unrepaired, lead to melanoma
- UV exposure = Vitamin D production
- Higher Vitamin D levels = may lead to lower incidence of melanoma
As you can see UV exposure seems to cause melanoma and increase Vitamin D levels which may reduce melanoma.
An award winning medical journalist recently wrote a well thought out article talking about the health of a suntan. However, if you take only that away from this article, it would be a mistake in our opinion.
Dermatologists in the US are very clear that Vitamin D production is limited with sun exposure. So while 10-15 minutes sun exposure will increase Vitamin D, after that it will start to lower it again.
The relationship between melanoma, Vitamin D and UV exposure is indeed complicated. But there are some very clever scientists working very hard to help figure it out.
For the time being, we’re going to enjoy the sunshine responsibly. We’re not going to avoid it but we are going to make sure we limit the amount of UV we expose our skin to.