The sun’s UV rays are bright enough to dazzle your eyes but they are also bright enough for your skin to absorb harmful ultraviolet rays.
So it’s not surprising that, as our sun grows older, we are more susceptible to UV damage.
But how much does UV damage actually damage us?
There is good news, says Udo Schulz of the German Institute of Physical Medicine and Rehabilitation, as he is the first to point out that the sun can be used to treat skin problems.
“There are studies that show that people who are exposed to ultraviolet light, for example, the sun in the winter, can actually have a beneficial effect on their skin,” he says.
But it is still not clear whether exposure to ultraviolet sunlight increases the risk of developing skin cancer.
So, in an attempt to understand how UV damage affects skin, Schulz set about creating a model that looked at the relationship between UV exposure and skin cancer risk.
To do so, he analysed the sunspot numbers in the skin of a group of European men and women who had been exposed to UV for longer than seven years.
The researchers then compared those figures to a group that had been treated with a skin cream that contained vitamin C. For the women, vitamin C seemed to protect them from UV damage but not the men.
This, he says, suggests that vitamin C might actually protect against UV damage because it is a sun protective factor.
What’s more, the researchers found that vitamin D might actually boost the risk, as it boosts the production of collagen, the connective tissue that makes up skin.
In other words, vitamin D levels in the UV-exposed group were more than 10 times higher than in the control group.
Furthermore, Schulz says, people with a higher vitamin D level are more likely to be at risk of skin cancer, as well as skin damage from UV exposure.
If the UV exposure is too high, this would be a huge issue.
“The more exposure you have to UV, the more you get exposed to damage,” he explains.
Schulz has recently developed a model of skin that uses skin thickness and the UV index, a measure of the amount of UV radiation that the skin is exposed to, to predict whether people will be at higher risk of cancer.
This is the same model that is used by sunscreen companies to sell their products.
These two models were used to create a model based on UV exposure, which revealed that skin thickness was the biggest risk factor for UV-induced skin cancer in men.
This suggests that it is vitamin D that could actually protect the skin against UV-related damage.
It’s not just skin thickening that might play a role, but it also plays a role in the formation of skin cell structures that make up skin, says Schulz.
Because UV exposure has been linked to increased risk of melanoma, skin thickness is also an important risk factor, he adds.
And skin thickness has a very important role to play in melanoma growth, as melanoma cells are more resistant to treatment.
So the study suggests that the relationship might extend beyond skin thickness.
“If UV exposure leads to increased melanoma cell formation, we should see increased risk for other cancers, as they also increase the size of melanomas,” says Schulzen.
That is, UV exposure increases the chance of developing melanoma.
One caveat, however, is that the researchers used a model with just 1,000 sunspot days to look at, whereas UV exposure for people who have been exposed for years to UV can take up to 3,000.
So these people are more exposed to the sun and therefore, the model was limited.
But the researchers are hopeful that this will be a useful way to measure risk in the future. ###