Photoaging

Photoaging is the term applied to skin changes due to light exposure (unlike chronological or intrinsic aging which is due to the passage of time).  As well as the rainbow of visible colours, sunlight is made up of rays invisible to our eyes. Skin-damaging ultraviolet light, invisible to the human eye, is grouped by wavelength:

  • UVC – shortest wavelength and most damaging, but is completely filtered out by the ozone layer.
  • UVB – 90% removed by the ozone layer. Unfortunately New Zealand’s ozone layer is compromised meaning we need to be even more vigilant regarding sun exposure. UVB is strongly related to skin cancer formation, but also photoaging of the skin.
  • UVA – longest wavelength grouping.  It is strongly associated with skin aging changes.  It has less ability to trigger skin cancer, but approximately one hundred times more UVA waves reach us than UVB waves.

The mechanism of photoaging is not completely understood, but it is suggested that in response to UVA and UVB exposure highly destructive chemical elements, termed ‘free radicals’, are generated.  Free radicals cause DNA mutations, as well as structural and enzymatic protein alterations.  Ultraviolet light also stimulates a chemical chain reaction that ultimately leads to increased enzymatic breakdown of collagen.

There is no such thing as a safe tan.  Every tanning reaction, including sun bed tanning, is a sign of skin distress.

To prevent damage to your skin from the sun, be sure that your sunscreen is your number one skin care product. It should be applied every day as part of your normal routine, like cleaning your teeth. Other things to consider are:

  • Stay inside between 11am and 2pm in summer – have lunch, feed the kids, have a siesta.
  • Don’t abuse sunscreens by using them to overstay your welcome in the sun.
  • At all times seek and rely on the shade of adequate clothing, umbrellas, trees and hats.
  • Don’t be fooled by cloudy days or cooling winds as UV rays are still present.
  • Do not sunbathe and never use tanning beds.