Chairman Warwick L. Morison, MB, BS, MD, FRCP, Professor of Dermatology, Johns Hopkins Medical School at Green Spring, MD.
John H. Epstein, MD, Clinical Professor of Dermatology, University of California at San Francisco.
Heidi Jacobe, MD, Assistant Professor, Dermatology, University of Texas Southwestern Medical Center at Dallas.
Henry W. Lim, MD, Chairman, Department of Dermatology, Henry Ford Medical Group, Detroit.
Steven Q. Wang, MD, Director of Dermatologic Surgery and Dermatology, Memorial Sloan-Kettering Cancer Center at Basking Ridge, NJ.
Reprinted with permission from the Photobiology Committee of The Skin Cancer Foundation, 149 Madison Avenue, Suite 901, New York, NY 10016.
SKIN CANCER FOUNDATION SUNSCREEN STATEMENT
If Recent Attacks on Sunscreen Concern You…
Since its inception in 1979, The Skin Cancer Foundation has always recommended using a sunscreen with a sun protection factor (SPF) of 15 or higher as one important part of a complete sun protection regimen. Recent attacks on sunscreens by the Environmental Working Group (EWG) and by the media point to imperfections and potential risks but miss the point that sunscreen continues to be one of the safest and most effective sun protection methods available.
We are concerned that the criticisms will raise unnecessary fears and cause people to stop using sunscreen, doing their skin serious harm.
In general, the criticisms have not been based on hard science. In fact, The Skin Cancer Foundation's Photobiology Committee, an independent volunteer panel of top experts on sun damage and sun protection, reviewed the same studies reviewed by the EWG and found that their determination of what made a sunscreen bad or good was based on "junk science."
Here, the Photobiology Committee responds to the criticisms and explains why sunscreen remains an essential part of anyone's daily sun safety program.
As sunscreen use has gone up in the past 30 years, so has melanoma incidence. Systematic review of all studies from 1966 to 2003 shows no evidence to support the relationship between sunscreen use and increased risk of melanoma, the deadliest form of skin cancer. Actually, some important epidemiological research has indicated that population groups using sunscreen have reduced their melanoma incidence.
The use of excessive SPFs and terms such as "broad-spectrum protection" or "multispectrum protection" on sunscreen labels mislead us into a false sense of security, when sunscreens really do not protect adequately against UVA radiation. Because both ultraviolet A (UVA) and ultraviolet B (UVB) are harmful, you need protection from both kinds of rays. "Broad-spectrum protection" and "multispectrum protection" mean only that a sunscreen offers protection against parts of both the UVA and the UVB spectrum. It does not mean complete protection. Because there is no consensus on how much protection the terms indicate, they may not be entirely meaningful. SPF refers specifically to how much protection is offered against UVB rays, but to date in the United States, we have no equivalent measurement to represent the degree of UVA protection in a sunscreen. Nonetheless, UVA protection in sunscreen has greatly improved in recent years. To make sure you are getting effective UVA as well as UVB coverage, look for a sunscreen with an SPF of 15 or higher, plus some combination of the following UVA-screening ingredients: stabilized avobenzone, ecamsule (also known as Mexoryl), oxybenzone, titanium dioxide, and/or zinc oxide.
For everyday use, an SPF of 15 or higher is generally adequate, while SPFs of 30 or higher are appropriate for active, extended outdoor activity. An SPF 15 sunscreen screens out 93% of the sun's UVB rays, whereas SPF 30 protects against 97% and SPF 50 against 98%. The Skin Cancer Foundation agrees that in most cases, SPFs beyond 50 are unnecessary.
Sunscreen blocks vitamin D. Although solar UVB is one source of vitamin D, the benefits of exposure to UVB cannot be separated from the harmful effects of sun exposure: skin cancer, cataracts, immune system suppression, and premature aging. In addition, excessive exposure to the sun actually depletes our body's supply of vitamin D. The safest way to obtain vitamin D is through a combination of diet and vitamin D supplements. The Skin Cancer Foundation recommends increasing your intake of vitamin D to 1,000 mg daily.
The sunscreen ingredient oxybenzone may be a carcinogen. Old research on rodents suggested that oxybenzone, a synthetic estrogen, can penetrate the skin, may cause allergic reactions, and may disrupt the body's hormones, producing harmful free radicals that may contribute to melanoma. However, there has never been any evidence that oxybenzone, which has been available for 20 years, has any adverse health effect in humans. The ingredient is approved by the Food and Drug Administration (FDA) for human use on the basis of exhaustive review. The Photobiology Committee reviewed the studies on oxybenzone and found no basis for concern.
Retinyl palmitate, a form of vitamin A and an ingredient in 41% of sunscreens, speeds up growth of tumors and other lesions when exposed to the sun. The EWG cites an FDA study for these data and faults the FDA for not releasing the study. However, the FDA is yet to release the study precisely because it has not gone through proper peer review. Thus, the EWG based its criticisms on an unapproved 10-year-old study of mice that has never been published in any journal. To date, there is no scientific evidence that vitamin A is a carcinogen in humans. What's more, only trace amounts of retinyl palmitate appear in sunscreens, and some evidence suggests that it is actually protective against cancer.
Nanoparticles in micronized zinc oxide and titanium dioxide may be more harmful than larger forms of these chemicals, crossing the placenta and affecting the developing fetus, or causing DNA damage linked to cancer. Micronized versions of zinc oxide and titanium dioxide were designed to improve them cosmetically so that they no longer left a tell-tale splotch of white on the skin. This improvement greatly increased the use of sunscreens containing these ingredients, which is a good thing because they are the two most effective ingredients to date in sunscreens against the entire UV spectrum. Multiple studies have demonstrated that the nanoparticles in these ingredients do not penetrate the skin, and there is furthermore no strong evidence of their toxicity. The general scientific consensus (which even the EWG now admits) is that they pose no risk to human health.
Criticisms have also been leveled against the Skin Cancer Foundation's Seal of Recommendation program, saying that sunscreen companies simply pay for use of the Seal. In actuality, manufacturers must provide scientific data on their sun protection product showing that it sufficiently and safely aids in the prevention of sun-induced damage to the skin. The data are reviewed by an independent volunteer team of photobiologists-experts in the study of the interaction between ultraviolet radiation and the skin. Every sunscreen product awarded the Seal is monitored annually to ensure that it continues to meet the criteria. The Seal of Recommendation requirements include
* an SPF of 15 or greater,
* validation of the SPF number by testing on 20 people,
* substantiated data that the product does not cause phototoxic reactions or contact irritation., and
* substantiation for any claims that a sunscreen is water sweat resistant.
The Skin Cancer Foundation also awards the Seal to other sun protection products, such as clothing, window film, awnings, hats, and sunglasses.
Consumers should rest assured that sunscreen products are safe and effective when used as directed and should be considered a vital part of a comprehensive sun protection program that includes the following sun safety strategies:
* Seek the shade, especially between 10:00 a.m. and 4:00 p.m.
* Do not burn. Wear a sunscreen with an SPF of 15 or higher every day.
* Apply 1 oz (2 tbsp) of sunscreen to your entire body 30 minutes before going outside. Reapply every 2 hours or after swimming or excessive sweating.
* Cover up with clothing, including a broad-brimmed hat and UV-blocking sunglasses.
* Keep newborns out of the sun. Sunscreens should be used on babies over the age of 6 months.
* Examine your skin from head to toe once every month.
* See your doctor every year for a professional skin examination.
* Avoid tanning and UV tanning salons.
© 2010 Lippincott Williams & Wilkins, Inc.