Tuesday, 06 February 2018 09:35

Shield Yourself From The Death Star! Featured

Shield Yourself From The Death Star

Living in Australia, we are very aware of the need to protect ourselves against the harmful effects of the sun, but how does the light actually damage our skin?

Light is made up of visible and invisible components and it is the short wavelength light in the ultra-violet component (UV light) that causes the trouble. In turn this UV light is subdivided into UVA, UVB and UVC depending upon the wavelength. The most powerful of these is UVC, which is filtered out by the earth’s ozone layer and so poses no threat.

UVA and UVB light both make it to the earth’s surface and can both damage skin. UVA light is the more plentiful and is shielded by neither normal glass nor clouds and so on balance is the more likely to lead to skin changes. We also can’t feel its effects on our skin while we are exposed.

The UVA and UVB light rays penetrate the skin and damage the DNA in dividing cells in the epidermis, which is the upper layer of the skin. The body has mechanisms to repair this damage or prevent these cells from surviving but sometimes this process fails. In this instance the cell with the damaged DNA may start to grow and replicate uncontrollably. This is a skin cancer.

The type of skin cancer will depend on the type of cell that has been damaged. The most serious of these is a melanoma where the melanin producing cells called melanocytes are damaged and turn cancerous. Other cells in the epidermis such as basal cells and squamous cells can also be damaged to produce basal and squamous cell carcinomas, which are the most common types of skin cancer.        

Melanin is a chemical produced by the melanocytes and is the cause of our skin pigmentation and tanning. It is distributed in small packets through all the cells of the epidermis and helps to shield the DNA of the cells from the damaging UV light. An abundance of melanin in the skin is one reason why darker skinned people are less likely to develop skin cancer.

Apart from causing skin cancer UV light, particularly UVA, can penetrate deeper into the skin and damage cells and proteins in the dermis. This damage leads to the effects of solar aging in the skin. Proteins such as elastin and collagen are damaged and stretched leading to wrinkles, skin sagging and some colour changes of aging skin. Blood vessels can be damaged causing increased capillaries to be visible under the skin.

So the sun’s UV light is to blame for the damage to our skin. Unfortunately we can’t feel its effects until it is too late. So next time you are going out in the sun try to visualise those UV rays crashing into your DNA like some beam from the Death Star and make sure your shields are up. “Engage the Slip, Slop, Slap, Mr Spock!”