• Question: why does the sun make your hair lighter and your skin darker?

    Asked by loulouc95 to MarkF, Mark, Michael, Panos, Sarah on 23 Jun 2010 in Categories: .
    • Photo: Michael Loughlin

      Michael Loughlin answered on 23 Jun 2010:

      well its down to what the sun does to us…and that is damage our DNA…not rapids but long term exposure to strong Ultraviolet light damages our DNA ( nad bacterias which is why we use UV to kill them sometimes)
      so in hair and skin their are pigments called melanins of which there are many types. These protect the DNA from damage..and are present in hair and skin

      Hair: melanin in this is bleached by the sun, and because hair cannot ptoduce anymore thats it the melanin is gone so the pigment is gone and the hair gets lighter…less pigment

      Skin: well skin cells are alive so they can react to this damaging of the DNA by increasing the amount melanin produced so protecting the DNA and darkening the skin.
      We allhave in our genes instructions for the top limit of melanin and the type ( some is dark brown…others more red) so we all tan diffferently

      hope that helped

    • Photo: Mark Fogg

      Mark Fogg answered on 23 Jun 2010:

      I’m fair skinned so I just turn pink and generally have a bit of ‘too much sun’ phobia because of it, besides, who wants to get skin cancer? 😉

      I remember answering a similar question to this last week so the first part is easy. The UV part of the sun’s spectrum causes Melanin in your skin to darken, the darker it is the more protection your skin gets. Additionally, your skin produces more Melanin, which in turn reacts with the UV and becomes darker. Naturally darker skinned people have more Melanin in the first place.
      For the second part, the hair lightening, Google says (see link below) it’s due to the breakdown of Melanin in the hair, speeded up by the sun’s UV. Hair that’s already grown can’t replenish its pigment, only new hair growth will, initially, be the original colour. So UV both increase the rate of Melanin production and it’s breakdown. Curious, might have to go rummaging around to find out more on the Chemistry of that.
      http://www.straightdope.com/columns/read/1006/why-does-the-sun-darken-skin-but-lighten-hair

    • Photo: Panos Soultanas

      Panos Soultanas answered on 23 Jun 2010:

      Hello,

      The sun induces destroys melanin and induces the skin to make more melanin to protect you from the damaging radiation of the sun. Hair also has melanin that gives it its specific colour. there are different types of melaning causing the different types of hair colouration. But when the sun destroys the melanin in the hair it is not replenished and so the hair becomes lighter.

    • Photo: Sarah Burl

      Sarah Burl answered on 23 Jun 2010:

      The sun induces production of skin pigment in the cells of the skin to help protect the skin however too much sun will lead to sunburn and that often results in skin cancer latter in life as the sun’s UV rays actually damage the DNA of the skin. The same pigment is in hair but the big difference os that the hair is dead so the sun destroys the pigment but it doesn’t produce more.

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