Dr. Hari Bezwada, MD
Ultraviolet Radiation
We have previously discussed how our skin is the fabric that wraps around our bodies, protects our vital organs, and provides a barrier to the outside environment. It can be damaged by the harmful effects of ultraviolet radiation. This damage can accelerate the aging process and ultraviolet radiation can be a major risk factor in the development of most skin cancers. Sunlight and tanning beds are the main sources of ultraviolet rays. UV rays damages our skin cells DNA leading to cancer. There are three main types of UV rays. UVA rays were originally thought to only cause aging and wrinkles, but they penetrate deeply and can damage cellular DNA leading to a developing role in skin cancer. Tanning beds give off UVA rays and these rays can also increase the skin cancer risk. UVB rays have more energy than UVA rays and more strongly associated with sunburns and may cause most skin cancers. UVC rays have more energy but don’t get through the atmosphere and are not a normal cause of skin cancer.
The strength of UV rays depends on a number of factors: time of day, season, distance from the equator, altitude, cloud cover, and reflection of surfaces. The amount of UV exposure one can get depends on the strength of the rays, duration of skin exposure, and whether the skin is protected with clothing or sunscreen. Frequent sunburns may increase the risk of some skin cancers years later. Long term exposure to UV rays can cause early skin aging, wrinkles, loss of elasticity, dark patches, and precancerous skin changes. UV rays may also increase the risk of cataracts.
Interestingly adequate sun exposure is important in vitamin D metabolism. Sunlight also has positive effects on mood through serotonin release. The key is to have careful sun exposure for its positive effects and minimize ultraviolet damage. That damage is best limited by using sunscreen that has a sun protection factor of 30 or greater and offers broad spectrum protection from both UA and UVB rays. It is very important to read the product labels carefully.
Since there are no certified organic sunscreens, a base application of organic skin moisturizer may be protective before applying sunscreen. It may also limit any skin absorption of the chemical ingredients in common sunscreens.