While most of my patients are skin cancer survivors and have learned the hard way why sunscreen is so important, many others have a hard time understanding why sunscreen is even needed.  In this three part series, I explain why we need sunscreen, how to choose the right one, and how to apply it correctly.


Reason #1: Ultraviolet Light Damages Your Skin

The sun emits ultraviolet (UV) light which causes damaging effects on our skin.  It causes skin inflammation, lowered skin immunity and DNA damage.   These stressors cause physical effects such as sunburn, photoaging, brown spots, wrinkles and skin cancer.

The UV light spectrum is divided into UVA, UVB and UVC.  UVC is filtered by the ozone, but UVA and UVB travel past the ozone layer to the earth’s surface.  UVA is most prevalent in our atmosphere and penetrates the skin more deeply. Collagen and blood vessels are located in the deeper layer of the skin and therefore UVA damage causes signs of photoaging, which includes wrinkles, blood vessels, and skin thinning.  In addition, about 20% of UVA rays pass through windows.  Which is why it is super important to wear sunscreen every single day, even if your only daily sun exposure is your drive to and from work.  UVB causes DNA damage in superficial skin cells which leads to the formation of skin cancers.

Ultraviolet light damage causes a number of skin changes including wrinkles, brown spots (lentigines), redness, and thin skin.  In addition, UV light exposure induces DNA damage in skin cells which causes skin cancers.  The most common skin cancers are basal cell carcinoma, squamous cell carcinoma and melanoma.

An important note to all those red heads out there – people with red hair have a different type of skin pigment called pheomelanin.  When pheomelanin reacts with UV light, it degrades and forms free radicals, which cause downstream DNA damage.  Thus, people with red hair are particularly susceptible to the UV light.

Reason #2: Wearing sunscreen protects your skin from the harmful effects of UV light

So, how do we prevent all this sun damage?  SUNSCREEN!  Regular sunscreen use can slow the process of photoaging. In addition, regular photoprotection can lead to the reversal of DNA damage, which can lead to a reduction in precancerous spots.

Stay tuned for Part 2 of this series: Choosing the Right Sunscreen