Skin Health and the Sun

Sunscreen Safety

There is a general consensus out there that if you spend more than 10 minutes in the sun, you should apply sunscreen to protect yourself from UV-induced damage, including skin cancer. Unfortunately, it is not that simple. First, sunscreen use blocks vitamin D production. Second, research is showing that sunscreens may not be as effective as their labels boast, and that they may, in fact, give people a false sense of security, in turn increasing the risk of skin cancer. Additionally, many of the common active ingredients found in sunscreens have been shown to have estrogenic properties, can be absorbed into the bloodstream, and actually create damaging free radicals in the skin.

While sunscreen use has increased in this country, so have skin cancer rates. The National Cancer Institute, the U.S. government’s principal agency for cancer research, concluded that there is no evidence that using sunscreen decreases the risk of skin cancer, including the deadliest form, melanoma. And, according to the Mayo Clinic, “Sunscreen is an important part of a sun-safety program, but by itself does not prevent squamous cell carcinoma or other types of skin cancer.”

The FDA, the agency that oversees the sunscreen industry, has set some guidelines for sunscreen manufacturers to follow. These guidelines include which chemicals and physical blocks are allowable in products, as well as what claims can be used on labels and what requirements must be met in order to use such claims. Even with such regulations in place, sunscreen in the US does not always offer the best available combination of safety and efficacy, and label claims can still be misleading. Furthermore, the FDA does not consider toxicity concerns, such as hormone disruption, when approving new sunscreen chemicals.

At Natural Grocers by Vitamin Cottage we do not carry chemical-based sunscreens such as oxybenzone, octinoxate and homosalate. These chemicals are absorbed into the skin and act as endocrine disruptors, altering reproductive and hormone function in lab animals, humans, and fish and other marine animals that come in contact with them.[1] [2] [3] [4] [5] [6]  In one study, chemical sunscreens were found to increase free-radical generation in the skin, which interferes with healthy skin cell function and is one of the ways UV rays damage the skin in the first place![7] Chemical-based sunscreens are also bad for the environment, contributing to the “bleaching” of coral reefs, which cause reefs to die.[8]

UVB vs. UVA

There are two main types of UV radiation that are known to contribute to skin cancer, wrinkling, and skin aging: UVA and UVB. UVB constitutes three to five percent of the total UV radiation that gets through the atmosphere, while UVA constitutes 95 to 97 percent. UVB, which penetrates only the outer skin layer, is what causes sunburn and is the primary cause of non-melanoma skin cancers, such as squamous cell carcinoma. In contrast, UVA can penetrate deeper into the skin where it can cause DNA damage and potentially cause more harm than UVB.

To get the most protection, you need to use a product that filters out a significant proportion of both types of rays. But while all sunscreens protect against UVB rays, only a few adequately protect against UVB and UVA rays. These products are usually labeled as UVA/UVB or “broad spectrum” sunscreens. Unfortunately, not all “broad-spectrum” sunscreens protect equally against the full spectrum of UVA rays and it isn’t always easy to tell from the label the degree of UVA protection you are getting.

There are only two FDA-approved sunscreen ingredients that block both UVB and UVA rays, that do not enter the bloodstream, and do not have estrogenic properties. They are titanium dioxide and zinc oxide and these are the only sunscreen ingredients you will find in our stores. Zinc oxide offers extensive protection against both UVB and UVA rays, while titanium dioxide offers extensive protection against UVB rays and considerable protection against UVA rays.[9] It is important to note, though, that one study showed that nanoparticles of zinc oxide (“micronized zinc oxide”) provoked oxidative stress (free radicals) in skin cells.[10]

Antioxidants and botanicals are also sometimes added to sunscreens since they help to prevent UV induced free-radical damage. In fact, one study from the University of California, San Francisco concluded that using antioxidant-rich creams and lotions may increase the safety and efficacy of sunscreens.[11] Look for formulations that include antioxidants such as green tea, vitamin E, rosemary extract, grapeseed extract, lutein, lycopene, astaxanthin, vitamin C, pomegranate extract and other antioxidants to counteract the oxidative stress created by UV exposure. For more information of the use of topical antioxidants and sun protection please see the Natural Grocers Customer Literature File Skin Health and the Sun—Antioxidant Skin Creams.

Sun Protection Factor (SPF)

It is important to note that the SPF rating tells you about UVB protection, but nothing about protection from harmful UVA rays, which also contribute to photo-aging and cancer. An SPF of 15 screens about 93% of the sun’s UVB rays, while an SPF of 30 screens about 97% and an SPF of 50 screens 98%. The FDA has proposed a regulation that would prohibit companies from labeling sunscreens with an SPF higher than 50. The agency itself has stated that higher values are “inherently misleading,” given that “there is no assurance that the specific values themselves are in fact truthful…” and that they do not “have adequate data demonstrating that [they] provide additional protection compared to products with SPF values of 50.”[12] As of yet, they have not enacted such regulation. More important than seeking out ultra-high SPF products is that you apply your sunscreen generously—most people put on only a quarter to two-thirds enough sunscreen to actually reach the product’s SPF rating. For the best sun protection, apply a generous amount of sunscreen to all exposed skin (the average adult needs approximately 2 tablespoons of sunscreen to adequately cover the body) and reapply every two hours or after sweating, swimming or towel drying.

Protection from the Inside Out

In addition to using sunscreens, it is important to protect your body from UV- induced damage with an antioxidant-rich diet, including lots of fruits and vegetables and supplementation with key antioxidants. For more information on the foods and supplements that help to protect your skin from the inside out please see the Natural Grocers Customer Literature File Skin Health and the Sun—Internal and External Protection.

There is no single product that provides 100 percent protection from UV damage. Protecting your body takes a multi-faceted approach, but with the right combination of sunscreen, diet, supplements, and skincare your body will be well armed to soak up the sun.

Each year the Environmental Working Group puts out a Sunscreen Guide that evaluates the safety and efficacy of many commercial sunscreens. To see how your sunscreen stacks up or to learn more about sunscreens go to www.ewg.org

Sunscreen Products Available at Natural Grocers (pdf download)

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2015-07-01 09_59_42-vcintranet_HO_nutrition_Nutritionist Files_Customer Literature Files by Subject_

 


References

[1] Dewalque L, Pirard C, Dubois N, Charlier C. Simultaneous determination of some phthalate metabolites, parabens and benzophenone-3 in urine by ultra high pressure liquid chromatography tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci. 2014;949-950:37-47.

[2] Wang L, Kannan K. Characteristic profiles of benzonphenone-3 and its derivatives in urine of children and adults from the United States and China. Environ Sci Technol. 2013;47(21):12532-8.

[3] Kunisue T, Chen A, Buck Louis GM, et al. Urinary Concentrations of Benzophenone-type UV Filters in US Women and Their Association with Endometriosis. Environ Sci Technol. 2012;46(8): 4624-4632.

[4] Schlecht C, Klammer H, Jarry H, Wuttke W. Effects of estradiol, benzophenone-2 and benophenone-3 on the expression pattern of the estrogen receptors (ER) alpha and beta, the estrogen receptor-related receptor 1 (ERR1) and the aryl hydrocarbon receptor (AhR) in adult ovariectomized rats. Toxicology. 2004;205(1-2):123-130.

[5] Krause M, Klit A, Bloomberg JM, et al. Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. Int J Androl. 2012;35(3):424-436.

[6] Coronado M, De Hara H, Deng X, et al. Estrogenic activity and reproductive effects of the UV-filter oxybenzone (2-hydroxy-4-methoxyphenyl-methanone) in fish. Aquat Toxicol. 2008;90(3):182-187.

[7] Hanson KM, Gratton E, Bardeen CJ. Sunscreen enhancement of UV-induced reactive oxygen species in the skin. Free Radical Biology and Medicine. 2006;41(8):1205-1212.

[8] Danovaro R, Bongiorni L, Corinaldesi C, et al. Sunscreens Cause Coral Bleaching by Promoting Viral Infections. Environ Health Perspect. 2008;116(4):441-447.

[9] n.a. Sunscreen: The Burning Facts. Environmental Protection Agency. September 2006. Available at: http://www.epa.gov/sunwise/doc/sunscreen.pdf

[10] Sharma V, Shukla RK, Sexena N, Parmar D, Dad M, Dhawan A. DNA damaging potential of zinc oxide nanoparticles in human epidermal cells. Toxicity Letters. 2009;185(3):211-218.

[11] Dreher F, Maibach H. Protective effects of topical antioxidants in humans. Curr Probl Dermatol. 2001;29:157-164.

[12] FDA Sheds Light on Sunscreens. U.S. Food and Drug Administration. May 17, 2012. Available at: http://www.fda.gov/forconsumers/consumerupdates/ucm258416.htm