The great sunscreen debate: Which type is best for you?

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Sunlight consists of UVA and UVB radiation. The UVA rays penetrate deeper into the skin and cause premature skin aging. Alternatively, UVB rays are what cause our skin to “tan” and “burn.” Although each causes its own damage, both are linked with skin cancer. For this reason, we should apply broad-spectrum sunscreen to all exposed skin every time we go outside.

Research shows one of five Americans will be diagnosed with skin cancer. The three main types of skin cancer are basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). BCC is the most common and fortunately has the least chance to metastasize. SCC is the next most common and has a minimal chance of spreading. MM, however, is the worst of the three and has the highest chance of metastasizing. Most importantly, using sunscreen can decrease the incidence of all three.

What we know as “sunscreen” actually falls into the broad category of photoprotective agents. The two main photoprotective agents are sunblock, which is opaque and “blocks” the sun; and sunscreen, which is translucent and must be reapplied frequently. Two important ingredients to look for in a sunblock are titanium dioxide and zinc oxide. Both act by reflecting UV rays and do not degrade in sunlight. For this reason, they are recommended for use in children and those with sensitive skin. Newer zinc oxide and titanium dioxide containing products are micronized, which allows them to “disappear” into dark skin. Alternatively, avobenzone is the best-known chemical in sunscreens, and is the most widely used organic ingredient. When purchasing photoprotective agents, ingredients to avoid are para-aminobenzoic acid (PABA), oxybenzone, homosalate and octinoxate. People with allergy-prone skin, acne, or rosacea should avoid products with fragrances as these may exacerbate their conditions. For dry skin, choose a sunscreen with moisturizers such as lanolin, oils or dimethicone.

For minimal sun exposure such as walking to your car, SPF 15 is sufficient. With extended time in the sun, SPF 30 or greater is advised. Additionally, although a product may be water- or sweat-resistant, it is still recommended to apply at least 30 minutes before sun exposure and reapply every two hours or after toweling off. The two biggest reasons sunscreens fail is under application and failure to reapply. A normal-sized adult should use one ounce (capacity of a shot glass) of sunscreen each application to cover from head to toe. The most commonly uncovered parts are feet, upper back, bikini area and hands.

In conclusion, the best advice to avoid premature skin aging and the risk of skin cancer is to avoid direct sun exposure between 10 a.m. and 3 p.m., reapply sunscreen at least every two hours, spend most of your time in the shade while outside and wear a wide-brimmed hat and long sleeves when in the sun. The next time you go to the store, remember the best sunscreen is whichever one you will consistently use.  

Joshua Patton is a fourth-year medical student hoping to obtain a residency in dermatology. Megan Barber is a fourth year pharmacy student. Patton is a student of Dr. Melinda Greenfield, a local dermatologist in Ponte Vedra Beach who is an associate professor at the GA PCOM campus in Atlanta. Her office in Ponte Vedra is located at 520 A1A North, Suite 230, near the Ponte Vedra Library. She welcomes adults and children of all ages to her practice.