Shining the Light on Sunscreens

by Kim Erickson

All-natural sun blocks provide the best protection against skin cancer.

Y ou’ve heard it before: Wear sunscreen. But just when Americans had become convinced that sunscreen could protect them from a future of premature wrinkles and skin cancer, new evidence is raising the question: Can sunscreen really help?

Although studies show that sunlight boosts our mental and emotional well-being while supplying 75 percent of the vitamin D our bodies require to metabolize calcium, dermatologists and skin care professionals have issued stern warnings that overexposure to the sun’s ultraviolet rays can make us look old before our time and increase the risk of skin cancer. And, according to Margaret Kripke, Ph.D., Department Chair of Immunology at the University of Texas, M.D. Anderson Cancer Center in Houston, recent research shows that UV radiation not only suppresses the immune response of skin cells, but may also induce a generalized suppression of the body’s immune system. The American Cancer Society estimates there will be 44,200 cases of skin cancer this year alone. Of those, approximately 7,300 people will die from it.

To prevent becoming one of the statistics, most dermatologists suggest a generous daily dose of sunscreen. But over the past decade some researchers have begun to question the safety and effectiveness of chemical sunscreens. The controversy stems from a parallel rise in skin cancer and sunscreen use. In February 1998, epidemiologist Marianne Berwick, M.D., of the Memorial Sloan-Kettering Cancer Center in New York City presented an evaluation of several studies on sunscreen use and cancer at an annual meeting of the American Association for the Advancement of Sciences. Her conclusion: There is no scientific evidence that the use of sunscreen prevents skin cancer. More frightening still, five of the studies Berwick cited found that the risk of melanoma was increased among sunscreen users.

While some experts believe that sunworshippers use sunscreen as an excuse to spend too much time in the sun, others suspect that the sunscreen ingredients themselves may be the culprit. “Some sunscreens have, at least in theory, the potential to inflict damage,” says Dr. John Knowland of the University of Oxford in England, whose research indicates that sunscreens containing PABA and its derivatives, such as Padimate-O, can damage DNA. 1 Other scientists have found PBSA (2-phenylbenzimidalzone-5-sulfonic acid), a UV-B filter widely used in sunscreens, capable of attacking DNA. 2 And other chemical UV blockers, such as cinnamates and avobenzone (also known as Parsol 1789), can cause allergic reactions.

So what’s a timid tanner to do? Fortunately, Mother Nature has supplied her own UV screening agents. Zinc oxide and titanium dioxide are natural minerals that create a physical barrier on the skin. Unlike sunscreens, which absorb ultraviolet light, these sunblocks scatter UV rays away from the skin’s surface. Often paired with botanical sunscreens such as shea butter, wild pansy, green tea and coffee extracts, these minerals safely protect against both UVA (the rays that suppress the immune system and promote melanoma, the deadliest form of skin cancer) and UVB (the rays leading to the less serious squamous and basal-cell skin cancers.

Antioxidants also can play a role in protecting skin from UV damage. According to a study published in the Journal of the American Academy of Dermatology , vitamins C and E not only protect against UV damage when applied topically, these antioxidants may provide extra protection against the sun’s scorching rays when taken internally before exposure. 3

Practicing sun sense also can minimize the risks of photodamaged skin and skin cancer. Those with the highest risk — fair skinned folk who burn and freckle easily or those with a family history of melanoma — should take steps to protect themselves, says Berwick. Look for a natural sunblock with an SPF rating of 15 of higher and limit your exposure to 15 to 30 minutes a day, especially between the hours of 10:00 a.m. and 3:00 p.m., when the sun is the strongest. If you know you’re going to be exposed for longer periods, the American Cancer Society advises covering up with long sleeves and pants and donning a wide-brimmed hat to shade delicate facial skin. It’s also wise to check your skin monthly for changes in moles or blemishes. If you notice any changes in their size, shape or color, see your doctor.

References:

1. Knowland J, et al. Characterisations of DNA damage inflicted by free radicals from a mutagenic sunscreen ingredient and its location using an in vitro genetic reversion assay. Photochemical Photobiology . 1997; 66:276.

2. Davies J. Sunscreen Ingredient Causes DNA Damage in Light. Chemical Research in Toxicology . 18 January 1999.

3. Eberlein-Konig B, et al. Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). Journal of the American Academy of Dermatology . 1998; 38:45-48.

More tips on natural sun care – and formulas for making your own non-toxic sun care products – can be found in Drop Dead Gorgeous: Protecting Yourself from the Hidden Dangers of Cosmetics.

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Kim Erickson.
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