Sun Facts
A Light Touch
Effective Facials and Skin Care
We all love the sun! Its warm soothing rays
Sun Facts...
A Light Touch
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| Sun damaged skin, also known as photo damage can be either acute, as in a sunburn or more commonly, seen as gradual changes in the skin caused by sun exposure throughout one's life. Chronic photo damage results in either a cosmetic change in the skin's appearance called photo aging, or changes that are of medical and health concerns such as pre-cancerous lesions and skin cancers. The evidence is very strong that ultra-violet light is the cause of most of the changes that we consider to be associated with aging of the skin. Sunlight causes premature skin aging, skin cancer, and a host of skin changes. Exposure to ultraviolet light, UVA or UVB, from sunlight accounts for 90% of the symptoms of premature skin aging. Many skin changes that were commonly believed to be due to aging, such as easy bruising, are actually a result of prolonged exposure to UV radiation. UVA Radiation UVA was once thought to have a minor effect on skin damage, but now studies are showing that UVA is a major contributor to skin damage. UVA penetrates deeper into the skin and works to bring about premature aging. The intensity of UVA radiation is more constant than UVB without the variations during the day and throughout the year. UVA is also not filtered by glass. UVB Radiation UVB affects the outer layer of skin, the epidermis, and is the primary agent responsible for sunburns. It is the most intense between the hours of 10:00 am and 2:00 pm when the sunlight is brightest. It is also more intense in the summer months accounting for 70% of a persons yearly UVB dose. UVB cannot penetrate through glass. Damaging Effects of UVA and UVB Both UVA and UVB radiation can cause skin damage including wrinkles, lowered immunity against infection, aging skin disorders, and cancer. However, we still do not fully understand the process. Some of the possible mechanisms for UV skin damage are collagen breakdown, the formation of free radicals, interfering with DNA repair, and inhibiting the immune system. Collagen Breakdown In the dermis, UV radiation causes collagen to break down at a higher rate than with just chronologic aging. Sunlight damages collagen fibers and causes the accumulation of abnormal elastin. When this sun-induced elastin accumulates, enzymes called metalloproteinases are produced in large quantities. Normally, metalloproteinases remodel sun-injured skin by manufacturing and reforming collagen. However, this process does not always work well and some of the metalloproteinases actually break down collagen. This results in the formation of disorganized collagen fibers known as solar scars. When the skin repeats this imperfect rebuilding process over and over wrinkles develop. Free Radicals UV radiation is one of the major creators of free radicals. Free radicals are unstable oxygen molecules that have only one electron instead of two. Because electrons are found in pairs, the molecule must scavenge other molecules for another electron. When the second molecule looses its electron to the first molecule, it must then find another electron repeating the process. This process can damage cell function and alter genetic material. Free radical damage causes wrinkles by activating the metalloproteinases that break down collagen. They cause cancer by changing the genetic material, RNA and DNA, of the cell. Texture Changes Caused by the Sun UV exposure causes thickening and thinning of the skin. Thick skin is found in coarse wrinkles especially on the back of the neck that do not disappear when the skin is stretched. A condition called solar elastosis is seen as thickened, coarse wrinkling and yellow discoloration of the skin. A common effect of UV exposure is thinning of the skin causing fine wrinkles, easy bruising, and skin tearing. Skin Cancer Caused by the Sun The ability of the sun to cause skin cancer is a well-known fact. The 3 main skin cancers are melanoma, basal cell carcinoma, and squamous cell carcinoma. Melanoma is the most deadly skin cancer because it metastasizes more readily than the other skin cancers. It is believed that the amount of exposure of the skin to the sun before the age of 20 is actually the determining risk factor for melanoma. Basal cell carcinoma is the most common skin cancer and tends to spread locally, not metastasize. Squamous cell carcinoma is the second most common skin cancer, and it can metastasize although not as commonly as melanoma. The risk of getting basal cell carcinoma or squamous cell carcinoma is determined by a persons lifetime exposure to UV radiation and the persons pigment protection. |
Effective Facials and Skin Care