 Think slathering on the highest-number sunscreen at the beach or pool will spare you skin cancer and premature wrinkles? Probably not, if you're in the sun a lot. That's because you don't need a sunburn to suffer the effects that can lead to various types of skin cancer.
Sunscreens generally do a good job filtering out the ultraviolet rays that cause sunburn -- UVB rays. But with sunburn protection, many people get a false sense of security that keeps them under the harsh sun much longer. Experts say the best protection against the more dangerous UVA rays, that penetrate deep into the skin and are more likely to cause skin cancer and wrinkles, is a sunscreen are those that include zinc oxide, titanium dioxide or avobenzone. Consumers should also look for those that are water-resistant - often a dubious claim - and have an SPF of 30 or better, indicating strong protection against UVB rays, and apply liberally and often. More important, limit time in the sun, particularly from 10:00am to 4:00pm, and cover up, including wearing a hat and sunglasses.
Often, product labels are confusing or bear misleading claims. For example, the SPF, or sun protection factor, refers only to defense against the less harmful UVB rays; nothing about UVA. "I don't think people understand they're only getting protection from part of the spectrum," said Dr. Sandra Read, a spokeswoman for the American Academy of Dermatology. "You're accumulating this damage and you don't know it."
Many sunscreens say little about when to reapply -- doctors say at least every two hours and after swimming or sweating. Nor do they say much about how much to use, roughly two tablespoons for an adult. "Most people who use an SPF 15 get the protection equivalent to an SPF 5 because they put it on" too thinly, said Dr. Martin A. Weinstock, chairman of the American Cancer Society's skin cancer advisory group and a Brown University professor.
While a higher SPF number means more protection, the difference is small: SPF 15 blocks about 93 percent of UVB rays and SPF 50, often more expensive, blocks about 98 percent. Most sunscreens work by reacting chemically with the skin, so they don't start absorbing damaging rays right away and must be applied a half-hour before going outside, something many labels fail to note.
What is the doctor’s reaction?
 Still, doctors say people shouldn't abandon sunscreen: They probably should use more. "Sunscreens do protect against skin cancer," said Dr. Babar Rao, a dermatologist at Robert Wood Johnson Medical School in New Jersey. "We definitely still need sunscreen, even on a cloudy day." Research has shown heavy sunscreen use lowers risk of squamous skin cell cancer, which has a high cure rate if caught early. Another study found heavy sunscreen use in children reduces the number of moles, which can turn cancerous later, Weinstock noted.
Despite public education campaigns about avoiding sun exposure and tanning salons, skin cancer incidence is climbing. There will be about 62,000 melanoma cases and 7,900 deaths this year in the US the American Cancer Society estimates. There are more than 1 million annual cases of squamous and basal skin cancers, and about 2,800 deaths. Based on cancer patterns between 2000 and 2002, the U.S. National Cancer Institute predicts that 1 in 50 men and 1 in 75 women in the United States will develop melanoma during his or her lifetime. In 1960, only 1 in 600 Americans was expected to develop melanoma. Similarly, squamous cell carcinoma, the second most common skin cancer in the U.S., is increasing in its rates. Since the early 1980’s, the rate of this cancer has increased approximately 10% per year.
Still, this should not all be blamed on sunscreen. There are other factors that can be blamed for our increasing rates of cancer. For example, consider global warming. The ozone protection in the atmosphere has been decreasing. Ozone gas can’t absorb as many harmful solar rays as it used to absorb, so more rays pass through to us.
Sunscreens probably do prevent skin cancer—we have some evidence from studies that squamous cell carcinoma rates, at least, are lower for those individuals who are consistent about their sunscreen use. I say, slather it on.
What changes can I make now?
 To be safe in the sun, take the following steps:
• Apply generous amounts of sunscreen with a sun protection factor (SPF) of at least 15. Choose a product with a broad spectrum of protection against both ultraviolet A (UV-A) and ultraviolet B (UV-B) rays. Broad spectrum sunscreens are usually those products that include zinc oxide, titanium dioxide or avobenzone.
• Reapply your sunscreen every two hours if you will be staying in the sun. Also reapply sunscreen after going in the water, even if your product claims to be water-resistant.
• Use a sun protection product on your lips. For safety, choose one that has been made for use on the lips, and select one that has an SPF of 20 or more.
• Use sunscreen before short ventures into the sun, not only prior to full-day outings. Short bursts of intense sun appear to be the most dangerous exposures that can increase your risk for melanoma, especially if you get sunburned.
• Wear protective sunglasses, protective clothing (long sleeves and long pants) and a broad-brimmed hat. Sun visors and baseball caps may protect your face but they do not protect your ears or neck as well as a full-brimmed hat.
• When you have a choice about when to do an outdoor task or activity, avoid the peak hours of sun intensity (10 a.m. to 4 p.m.).
• Ask your doctor if your medications increase your sensitivity to the sun, because many medications make your skin more vulnerable to sun damage.
• Be aware that certain skin-care products sold in pharmacies contain chemicals called alpha-hydroxy acids. Alpha-hydroxy acids can make your skin more vulnerable to damage from sunlight.
• Avoid tanning salons. If you want to appear tan, use commercial sunless tanning creams.
What can I expect looking to the future?
No matter how careful you have been in the sun, we are all at risk for skin cancer. A skin cancer is a small problem if it is discovered right away, but it can be life-threatening if it is not quickly recognized.
Be especially attentive to your hands, arms, and face, since these are your most heavily sun-exposed areas. Watch for new moles, moles with irregular shape or coloring, existing moles that begin to change, or skin sores or scars that won’t heal. Watch for pink, brown, or yellowed spots of skin that feel scratchy, crusty or rough when you rub your finger over them. A spot like that may be a pre-cancer called “actinic keratosis.” Your doctor can freeze this type of spot with liquid nitrogen or can choose another way to eliminate it, so it does not have a chance to change into a squamous cell cancer. Bring suspicious moles or rough spots to your doctor’s attention without a delay. |
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