Keep Your Skin Safe This Summer
About half of young adults report getting at least one sunburn per year.1 As we plan to spend time outdoors this summer, we must remember to also avoid excessive sun exposure to protect ourselves from free radical damage and skin cancer. Recurrent sunburn may result in later life skin cancer.
Melanoma, the deadliest form of skin cancer, has been steadily on the rise since the 1970s and since 2000, melanoma incidence has risen at a rate of 1.6% per year.2 It is essential to protect your skin from the sun’s rays.
To keep our skin healthy, we must seek shade often, wear protective clothing, and avoid mid-day sun or too much time in the sun. Also, when choosing a sunscreen, it is important to use the safest and most effective methods of sun protection.
What about vitamin D?
Under our present atmospheric conditions, unprotected sun exposure for extended periods is not safe. We should not rely on the sun to provide all our needs for vitamin D because it needlessly increases the risk of skin cancer and premature aging of the skin. Supplementation with D3 is the safest method of obtaining sufficient vitamin D.
UVB rays cause sunburn; both UVA and UVB rays contribute to skin cancer. Many sunscreens do not protect against UVA rays. The SPF listed on sunscreens refers only to UVB protection.
Chemical sunscreen absorbs and deflects the sun’s rays away from the skin through a chemical reaction. Sunscreens vary in their ability to protect against UVB and UVA rays depending on the ingredients used.
Physical (mineral) sunscreen creates a physical barrier between the UVA and UVB rays and the skin. Physically blocking sunlight from penetrating the skin is the most effective way to block UVA and UVB radiation.
Sunscreen ingredients to avoid
Vitamin A is often listed on sunscreen labels as an antioxidant that can fight skin aging. Vitamin A is an antioxidant, but in isolation it could be dangerous, both in supplements and for the skin. According to animal studies, sunscreens may actually promote the progression of skin cancer if they contain vitamin A.3,4 The chemical sunscreen ingredients oxybenzone and OMC are the most concerning; they are endocrine disruptors – chemicals that have the ability to mimic, inhibit, or alter the action of the body’s natural hormones.5 Exposure to endocrine disruptors, for example BPA and DDT, have been linked to early puberty in children and hormonal cancers in adults.6,7 Endocrine disrupting effects of chemical sunscreens have been reported in animals, and they are likely to affect human health as well.8,9 A study by the Centers for Disease Control and Prevention found oxybenzone in the urine samples of 96 percent of the Americans tested; this suggests that oxybenzone is absorbed into the blood when chemical sunscreen is applied to the skin, and could therefore disrupt hormones in the body.10 Other studies have found sunscreen chemicals in breast milk.8-11 In observational studies, urinary oxybenzone has been linked to endometriosis, possibly due to its estrogenic effects.12 In addition, there seem to be significant rates of skin allergy to oxybenzone.13,14
Mineral sunscreens are safer than chemical sunscreens, but some mineral sunscreens are safer than others
Mineral sunscreens most commonly contain either titanium dioxide or zinc oxide or a combination of these two, and these are preferable to chemical sunscreens. These minerals do not penetrate as deeply into the skin as chemical sunscreens. They lie on top of the skin and penetrate only into superficial layers, absorbing UV rays before they can damage the skin beneath. Zinc oxide has been found to be superior to titanium dioxide in absorbing UVA rays.15
Certain products use nanoparticles of titanium dioxide and zinc oxide to make the sunscreen more easily absorbed by the skin and therefore more transparent; there have been concerns that these small particles could penetrate the skin and enter the bloodstream. The evidence so far suggest that these nanoparticles have a limited ability to penetrate the skin,16-18 however they could damage lung tissue if inhaled or enter the bloodstream and reach other organs if inhaled or ingested.19-21 Additional studies are needed in order to definitively determine whether nanoparticle-containing sunscreen products are safe.
Mineral sunscreen without nanoparticles is the safest choice
Mineral sunscreen is safer than chemical sunscreen, and non-micronized zinc oxide sunscreen is the safest choice for protecting against UVA and UVB rays. Unfortunately, sunscreen labels most often do not disclose whether the product contains nanoparticles.
I recommend and make available a safe and effective sunscreen line that uses nonmicronized zinc oxide. Green Screen® organic sunscreen protects against both UVA and UVB without the use of nanoparticles or harmful chemicals, and is made from all natural and edible grade organic ingredients. This product uses non-nano zinc oxide, the Environmental Working Group’s preferred sun protection ingredient with the best evidence for safety and effectiveness. Of all the mineral sunscreen products Green Screen® is one of the very few that does not contain nano- or micro-sized particles. We have contacted and communicated with the technical departments of many sunscreen companies to find a product that does not contain nanoparticles. Green Screen® does leave a tint on your skin when applied—that’s why it is available in both white and flesh tone. The advantage is that you can easily see whether you are protected and whether it is time to reapply the sunscreen.
1. Centers for Disease C, Prevention: Sunburn and sun protective behaviors among adults aged 18-29 years--United States, 2000-2010. MMWR Morb Mortal Wkly Rep 2012;61:317-322.
2. National Cancer Institute. Surveillance, Epidemiology, and End Results Program (SEER). Fast Stats. [http://www.seer.cancer.gov/faststats/ ]
3. Environmental Working Group. The problem with vitamin A. 2014. http://www.ewg.org/2014sunscreen/the-problem-with-vitamin-a/ . Accessed May 21, 2014.
4. Lunder S: Environmental Working Group. What Scientists Say About Vitamin A in Sunscreen. 2011. http://www.ewg.org/research/what-scientists-say-about-vitamin-sunscreen . Accessed May 21, 2014.
5. Krause M, Klit A, Blomberg Jensen M, et al: Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. Int J Androl 2012;35:424-436.
6. Roy JR, Chakraborty S, Chakraborty TR: Estrogen-like endocrine disrupting chemicals affecting puberty in humans--a review. Med Sci Monit 2009;15:RA137-145.
7. De Coster S, van Larebeke N: Endocrine-disrupting chemicals: associated disorders and mechanisms of action. J Environ Public Health 2012;2012:713696.
8. Schlumpf M, Durrer S, Faass O, et al: Developmental toxicity of UV filters and environmental exposure: a review. Int J Androl 2008;31:144-151.
9. Schlumpf M, Cotton B, Conscience M, et al: In vitro and in vivo estrogenicity of UV screens. Environ Health Perspect 2001;109:239-244.
10. Calafat AM, Wong LY, Ye X, et al: Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003--2004. Environ Health Perspect 2008;116:893-897.
11. Schlumpf M, Kypke K, Wittassek M, et al: Exposure patterns of UV filters, fragrances, parabens, phthalates, organochlor pesticides, PBDEs, and PCBs in human milk: correlation of UV filters with use of cosmetics. Chemosphere 2010;81:1171-1183.
12. Kunisue T, Chen Z, Buck Louis GM, et al: Urinary concentrations of benzophenone-type UV filters in U.S. women and their association with endometriosis. Environ Sci Technol 2012;46:4624-4632.
13. Schauder S, Ippen H: Contact and photocontact sensitivity to sunscreens. Review of a 15-year experience and of the literature. Contact Dermatitis 1997;37:221-232.
14. Szczurko C, Dompmartin A, Michel M, et al: Photocontact allergy to oxybenzone: ten years of experience. Photodermatol Photoimmunol Photomed 1994;10:144-147.
15. Pinnell SR, Fairhurst D, Gillies R, et al: Microfine zinc oxide is a superior sunscreen ingredient to microfine titanium dioxide. Dermatol Surg 2000;26:309-314.
16. Gulson B, Wong H, Korsch M, et al: Comparison of dermal absorption of zinc from different sunscreen formulations and differing UV exposure based on stable isotope tracing. Sci Total Environ 2012;420:313-318.
17. Filipe P, Silva JN, Silva R, et al: Stratum corneum is an effective barrier to TiO2 and ZnO nanoparticle percutaneous absorption. Skin Pharmacol Physiol 2009;22:266-275.
18. Sadrieh N, Wokovich AM, Gopee NV, et al: Lack of significant dermal penetration of titanium dioxide from sunscreen formulations containing nano- and submicron-size TiO2 particles. Toxicol Sci 2010;115:156-166.
19. Environmental Working Group. Nanoparticles in Sunscreens. 2014. http://www.ewg.org/2014sunscreen/nanoparticles-in-sunscreen/ . Accessed
20. Liu R, Zhang X, Pu Y, et al: Small-sized titanium dioxide nanoparticles mediate immune toxicity in rat pulmonary alveolar macrophages in vivo. J Nanosci Nanotechnol 2010;10:5161-5169.
21. Tang M, Zhang T, Xue Y, et al: Dose dependent in vivo metabolic characteristics of titanium dioxide nanoparticles. J Nanosci Nanotechnol 2010;10:8575-8583.