We are all familiar with the benefits of wearing a sunscreen to shield our skin from the sun's harmful rays. But new scientific discoveries show that the problem is both deeper and more dangerous than previously believed.

While some may perceive a glow on the skin after sun exposure to be a sign of health, in fact DNA damage is happening deep within the skin. The change in your skin's color after a few moments in the sun may be visible to everyone, but DNA damage is invisible. This invisible event is dangerous because DNA damage is the direct link to skin cancers and to premature aging.

The skin is comprised of three main layers: epidermis, dermis and hypodermis. (Illustration) Together they perform the role of protection, moisture retention and support. But most important is the fact that these layers know their roles because of the DNA deep inside each skin cell. Much like a computer program, DNA is the genetic material inside each cell that controls the cell's function. Once DNA is damaged, the skin cells lose their ability to perform their essential roles. Furthermore, damaged cells replicate abnormally and over the years, this damage accumulates accelerating skin aging and increasing your risk of skin cancer.

DNA damage largely occurs as a result of free radical attack. Free radicals are generated by many diverse factors, but are primarily the result of ultraviolet rays from the sun.

Ultraviolet rays are invisible; those most important to the skin are UVB and UVA rays. UVB rays penetrate the topmost layer of the skin. These rays are the primary cause of sunburn, as well as some skin cancers. UVA rays can penetrate deeper into the skin. UVA rays are more likely to cause longer-term effects such as wrinkling, discoloration, a leathery skin appearance, and possibly melanoma (the most serious type of skin cancer).

Contrary to popular belief, a sunscreen with a high SPF does not necessarily prevent DNA damage and resulting visible skin conditions. The reason for this is that SPF ratings measure only a sunscreen's effectiveness in blocking UVB rays. But in fact, UVA rays once thought to be harmless because they produce no burning actually penetrate much deeper into the skin leading to much more damage to DNA and other skin structures.

Scientific advancements continue to enable scientists to find more and more ways to support the skin's natural repair mechanisms. First, using broad-spectrum sunscreen daily is a must as it can protect the skin from the stresses caused by both UVA and UVB penetration, allowing the skin to focus on its normal job of cell repair and regeneration. Secondly, antioxidants can help neutralize free radicals and prevent DNA damage. And last, new technological advancements actually help boost the cell's natural repair process to reverse DNA damage.

Protecting your skin from DNA damage

• Follow a consistent, life long approach to healthy skin. Even minimal UV exposure can affect you're skin's DNA. Daily use of a broad spectrum sunscreen will help minimize the suns effect on the appearance of premature aging.
• Look for sunscreens that offer "broad-spectrum" or "UVA/UVB" protection or a "PA" rating.
• The safest option is to avoid sun exposure whenever possible. Minimize exposure between 10 am and 4 pm.
• When you go outside, even on a cloudy day, always apply a broad spectrum sun protection product of SPF 15 or higher.
• When outside for extended periods of time or after physical activity (e.g. swimming, tennis, etc.) reapply.
• Most people do not apply sufficient sun protection product. Be sure to follow instructions on the package.
• Use self-tanning formulas or bronzers if you desire the look of a tan. But remember that these products do not usually offer any sun protection, so you should always apply protection as well.
• Stay away from tanning salons. The International Agency for Research on Cancer (IARC), a branch of the World Health Organization (WHO), has unequivocally linked sunbed tanning among young people to melanoma, the deadliest form of skin cancer.
• Wear protective clothing that will cover arms and legs; choose a hat with a wide brim. Consider UV-protective products such as some window films, sunglasses, and clothing.