By MedHelp Editors
After months of wool sweaters and snow boots, it's hard to resist putting on your bathing suit, pulling up a lawn chair and soaking in the sun's warm rays. But fun in the sun comes with a dark shadow — skin cancer. With more than two million people diagnosed each year, skin cancer is the most common form of cancer in the United States, accounting for nearly half of all cancer cases in the U.S.
Ultraviolet (UV) radiation from the sun is considered the main cause of the most common types of skin cancer, and is also a key player in melanoma, the rarer but deadliest form of skin cancer. Because of this, you shouldn't take sun protection lightly.
Your best defense against sun damage is a good sunscreen. See our picks for the best buys and get the scoop on the latest ingredients to include — and avoid!
Your sunscreen label may read like one big alphabet soup. So you know what it's saying, and what to look for, let's start by decoding the most important terms.
• UVA rays: These are long wavelength UV rays that penetrate into the deeper layers of the skin, and are the main cause of skin aging, wrinkles and tanning.
• UVB rays: Of a shorter wavelength than UVA rays, UVB rays only penetrate the more superficial layers of the skin and cause the burning, redness and peeling we recognize as sunburn.
• SPF: Short for "sun protection factor," SPF is a measure of how well a sunscreen protects against UVB radiation only. The number printed on sunscreen packaging indicates how much time it takes for sun exposure to cause sunburn when sunscreen is used, versus the amount of time needed for a burn to appear on unprotected skin. For example, if it takes 1 minute of sun exposure for unprotected skin to burn, it would take 30 minutes for the same effect to appear on skin treated with the correct amount of SPF 30 sunscreen.
The Environmental Working Group (EWG), an environment and consumer watchdog organization, recently released its well-publicized 2011 Sunscreen Guide, a massive database of about 1,700 sun protection products, rated based on the effectiveness and safety of their ingredients as evaluated from their review of various scientific studies.
Among the sunscreen ingredients the group has put on its "hate" list are oxybenzone and a form of vitamin A called retinyl palmitate. Oxybenzone is a common component in sunscreens labeled "broad-spectrum" — they protect against both UVA and UVB radiation. EWG disputes the safety of oxybenzone based on studies that show the chemical's ability to penetrate the skin and act as a hormone disruptor. Retinyl palmitate, on the other hand, is a chemical included as an inactive ingredient in some products because of its antioxidant properties. The group flags products containing retinyl palmitate as harmful, citing a study done on mice which showed accelerated the formation of skin lesions and tumors resulting from sun exposure on skin treated with a cream containing retinyl palmitate.
David Moskowitz, MD, a board-certified dermatologist with Kaiser Permanente's Oakland Medical Center in Oakland, California, disagrees with the group's conclusions regarding the two substances. "I think that further study and concern is warranted for anything that we regularly apply to our skin and I support such research, but at this time, I have not seen evidence that has convinced me to recommend that my patients avoid these products," he said in an email interview.
He notes that the studies on oxybenzone were done on animals that were force-fed large amounts of the compound, and the associated harmful effects were very unlikely if not impossible to result from normal sunscreen use, even if a small amount is absorbed into the body through the skin. And while Dr. Moskowitz acknowledges that there have been studies that seem to indicate that retinyl palmitate speeds the development of skin cancer, these studies have not been widely reproduced, and there may have been another ingredient contributing to the tumor and lesion formation. In fact, retinoids like retinyl palmitate are used to prevent skin cancer in certain patients.