Ultraviolet light keeps damaging people’s skin even once they have come out of the sun’s rays, scientist’s research has revealed.

Yale University researchers say ultraviolet (UV) radiation continues to cause mutations to melanocycte cells hours after people have been exposed to sunlight. Reported in the journal Science it reverses the assumption that melanin, which is the pigment that gives skin its colour, is purely protective in blocking harmful UV.

Douglas Brash, of Yale Cancer Centre, said: “Melanin does act as a shield, but is doing both good and bad things.” The researchers found that the damage to DNA in Melanocytes occurs from both the sun and from tanning lamps.

DNA testing for effects of UV after exposure

The experiments were conducted on human and mouse samples with the cells continuing to experience DNA damage hours after the UV exposure had ended. With follow up DNA tests the team analysed DNA mutations in mouse cells exposed to sunlight to find that half of the mutation had been generated in the dark.

UV light activated two enzymes that combined to agitate an electron in melanin. This released energy that damaged the DNA in the dark, emulating the damage sunlight caused during the daytime.

Although this is likely to be a good indication of biochemical pathways that may occur in human skin cells after UV exposure, for the moment it is unclear whether the situation in humans is completely identical. The research is certainly a revelation as this process known as ‘chemiexcitation’ had previously only been observed in plants and lower order animals.

UV exposure and skin cancer

Skin cancers are one of the most common forms of cancer in the UK and are caused by damage from the sun’s UV rays. The NHS reports that in 2010 around 100,000 people were diagnosed with skin cancer in the UK. More than 12,000 of these cancers were malignant melanoma, the most serious type of skin cancer. Each year, around 2,200 people die from skin cancer.

Protecting the skin from the sun can help prevent these cancers, the NHS suggests a number of ways you can reduce the risk:

  • Spend time in the shade between 11am and 3pm.
  • Make sure you never burn.
  • Aim to cover up with a T-shirt, hat and sunglasses.
  • Remember to take extra care with children.
  • Then use factor 15+ sunscreen.

They also suggest reporting mole changes or unusual skin growths to your GP and that using sunbeds is not a safe alternative to lying in the sun as the skin is still exposed to harmful UV rays. It also says that using sunbeds before the age of 35 increases your risk of skin cancer by up to 75%.

The NHS says that you should not use sunbeds or other UV tanning equipment if:

  • you have been sunburnt in the past, particularly in childhood
  • you have fair skin that burns easily
  • you have a large number of freckles or red hair
  • you have a large number of moles
  • you’re taking medication that makes your skin more sensitive to sunlight
  • anyone in your family has had skin cancer in the past

Put your DNA in safe hands

From this Yale research and NHS advice we can see that it is important to keep your DNA safe, especially from UV radiation. It is good to know that there are things we can do about it and it is not impossible for us to help prevent some negative effects that can develop at a genetic level.

At AlphaBiolabs we strive for the highest standards in DNA testing, we remain 100% confidential, with a strict chain of custody and fully qualified sample collection team. So whenever you have a DNA test with us or a DNA sample collection you know that you are in safe hands. Much like it is important to take heed with NHS advice on UV exposure to limit damage to your DNA it is important to go with the best when it comes to the safe handling of your DNA testing needs.