Sunscreen and Skin Cancer
Apply sunscreen generously. Skimpy application can reduce the sun protection factor (SPF) by up to 50%.
Thanks to our love affair with the sun, skin cancer is on the rise. With this in mind, taking precautions becomes paramount. So what about sunscreen? Can sunscreen protect you from skin cancer?
This is an important question. With about a million new cases reported annually, skin cancer is the most common form of cancer. And these numbers don’t even include melanoma, the most serious form of skin cancer. Although most cases are highly curable, especially when detected early, treating skin cancer can be costly and difficult.
There are 3 forms of skin cancer: basal cell, squamous cell, and melanoma. Like other cancers, skin cancer is influenced by genetics, so those with a family history of skin cancer are at higher risk. The most obvious sign of this genetic relationship is skin type. Fair-skinned people are at greater risk than darker-skinned people. However, the major culprit in the rise of all forms of skin cancer, regardless of genetics, melanoma included, is sun exposure.
Years ago, a golden tan was considered unfashionable and people went to great lengths to protect themselves from the sun. Many of us have seen old photographs showing women at the beach in floor-length dresses with long sleeves. Gradually, however, modest outfits gave way to bikinis and generations of sun worshipers were born.
“Attitudes have changed. Years ago, the sun was thought of as something that should be avoided. Then, the shift was that the sun is good for you. Now, the shift is going back again,” says Martin A. Weinstock, MD, PhD, professor of dermatology at Brown University and chairman of the skin cancer advisory group of the American Cancer Society.
How the Sun Damages Skin
We used to think that it took decades for sun damage to accumulate, and that skin cancer developed no sooner than middle age. Now younger and younger people are being diagnosed. The majority of sun exposure is obtained by the age of 18. According to David J. Leffell, professor of dermatology and surgery at Yale School of Medicine and author of Total Skin (Hyperion, 2000), the reason for this change is not clear. “We see a definite trend of skin cancer increasing in young women and young men, but the reasons are not known. It could relate to more sun exposure because of more leisure time, or even increased use of tanning parlors,” he says. Light-skinned races, such as Caucasians, are the most vulnerable. But African-Americans and those with darker skin are not immune, although they develop skin cancer far less frequently.
What role does the sun play? The sun is a source of radiation, which it emits in 2 types of rays: UVA (ultraviolet A) and UVB (ultraviolet B). Although the UVA rays produce less skin redness than the shorter UVB rays, these longer rays are more damaging to skin cells. Ultraviolet rays not only cause skin cancer, but also cause other effects from the sun, such as wrinkles and age spots. These skin changes were once attributed solely to aging, but they are now recognized as the results of long-term sun exposure. Those who live in sunny climates year-round have higher skin cancer rates. But don’t be fooled; radiation from the sun can also occur on cloudy days, so sun protection is important no matter where you live and whether or not it’s sunny out.
How Sunscreens Protect You
Sunscreens are protective substances. They extend the length of the time you can be outside before your skin begins to redden. A study presented in 1998 at a conference of the American Association for the Advancement of Science looked at the sunning habits of people with melanoma. It questioned the value of sunscreen.¹ Still, the strong consensus of experts is that to discard it would result in even higher skin cancer rates. Instead, they noted that the study should be used as a warning that using sunscreen doesn’t give you liberty to stay out in the sun indefinitely, since damage to the skin cells is still occurring.
How to Pick the Right Sunscreen
You can judge the protectiveness of a sunscreen according to its SPF, which stands for Sun Protection Factor. For instance, if your skin usually turns pink after 10 minutes, a sunscreen with an SPF of 15 extends this to 2.5 hours (10 minutes multiplied by the “15” protection factor = 150 minutes). Here are some general recommendations for sunscreen from the American Academy of Dermatology.
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Check for ingredients that screen UVA: benzophenone, oxybenzone, sulisobenzone, titanium dioxide, zinc oxide, and butyl methoxydibenzoylmethane (also called avobenzone and known by the trade name Parsol 1789).
But if SPF 15 is good, isn’t a higher number better? Perhaps, but it depends on your individual characteristics. For instance, if you’re particularly fair skinned, live at a high altitude where the sun’s rays are stronger, or spend a lot of time outdoors, choose a sunscreen with an SPF number of 30.
How to Be in the Sun Safely
Follow these tips for safe sunning.
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Whether you prefer your sunscreen in the form of a cream, oil, lotion, or gel is up to you. However, some oils have very low SPF levels. Remember, too, that you need to reapply all sunscreens periodically, and you need to reapply gels more often. New continuous spray sunscreen may make it easier to apply sunscreen to hard-to-reach areas.
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Choose sunscreen labeled “waterproof” or “very water resistant” sunscreen. Also, chose a sunscreen labeled “broad spectrum,” meaning it screens out both UVA and UVB rays, but bear in mind that there is no standardized test for broad spectrum products.
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Use a sunscreen if you’re going to be outdoors for more than 20 minutes. Apply the sunscreen at least 30 minutes before going outdoors. If you’re going swimming, or if you’re doing an activity which causes you to sweat, reapply the sunscreen afterwards, and again every 2 hours.
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Protect your children as well. Teach older children safe sun habits. Teach toddlers about using sunscreen and how to apply it. Keep infants under 6 months out of direct sun, keep their skin covered, and use an umbrella over their stroller. Use sunscreen on them beginning at 6 months of age.
Tanning Beds and Sun Lamps
Many people believe that the UV rays of tanning beds are harmless because sunlamps in tanning beds emit primarily UVA and little, if any, UVB, the rays once thought to be the most hazardous. Plus, they are regulated by the Food and Drug Administration.
But no matter what the regulations say these lamps do emit UVA rays, and UVA rays can cause serious skin damage, too--including skin cancer. According to some scientists, UVA may be linked to the most serious form of skin cancer, melanoma. Because of sunlamps’ dangers, health experts advise people to avoid them for tanning.
Tanning Pills
Several products that claim to give a tan without UV radiation carry safety risks, too. These include so-called tanning pills containing carotenoid color additives derived from substances similar to beta-carotene, which gives carrots their orange color. The additives are distributed throughout the body, especially in skin, making it orange. Although FDA has approved some of these additives for coloring food, it has not approved them for use in tanning agents. And, at the high levels that are consumed in tanning pills, they may be harmful. They can lead to crystal deposits in the eyes , which may cause injury and impaired vision. There also has been one reported case of a woman who died from aplastic anemia, which her doctor attributed to her use of tanning pills.
Tanning accelerators, such as those formulated with the amino acid tyrosine or tyrosine derivatives, are ineffective and also may be dangerous. Marketers promote these products as substances that stimulate the body's own tanning process, although the evidence suggests they don’t work,. FDA considers them new drugs that have not been proved safe and effective.
Two other tanning products, bronzers and extenders, are considered cosmetics for external use. Bronzers, made from color additives approved by FDA for cosmetic use, stain the skin when applied and can be washed off with soap and water. Extenders, when applied to the skin, interact with protein on the surface of the skin to produce color. The color tends to wear off after a few days. The only color additive approved for extenders is dihydroxyacetone.
Although they give skin a golden color, these products do not offer sunscreen protection. Also, the chemicals in bronzers may react differently on various areas of your body, producing a tan of many shades.
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