Sunscreens - Are They An Oxymoron?

Jul 22, 2012 | HWN Team | Heads or Tails
Sunscreens - Are They An Oxymoron?

image by: Shélin Graziela

It's everywhere and everybody does it…uses sunscreen, that is. But could sunscreens be causing more harm than good?

There's sunscreen in just about every cosmetic and lotion available, as well as most lip balms throughout the planet. Yet, skin cancer including melanoma is on the rise, just look at Australia. According to WHO  “Currently, between 2 and 3 million non-melanoma skin cancers and 132,000 melanoma skin cancers occur globally each year”  and sun exposure is the biggest culprit. While melanoma accounts for only about 4 percent of all skin cancer cases, it causes almost 80 percent of skin cancer deaths.1 

The American Cancer Society’s awareness campaign for skin cancer prevention certainly simplifies the process with its slogan “Slip!  Slop!  Slap!  and Wrap,” a catch phrase that reminds people of the four key ways they can protect themselves from UV radiation: 

  • Slip on a shirt,
  • Slop on sunscreen,
  • Slap on a hat, and
  • Wrap on sunglasses to protect the eyes and sensitive skin around them from UV light.

If sunscreen is available in most products and seems to be universally accepted and used, why is skin cancer on the rise in populations that do less and less outdoor work? Could ‘slip, slop’…be causing more harm than good? Huh! Isn’t sunscreens supposed to protect your skin from the sun’s damaging rays? Well it does when it comes to acute sun exposure – no more painful burns. But, when sunscreens comes to protecting you from the effects of chronic sun exposure, it’s apparently another story!

Much of the latest information floating around about the safety and efficacy of sunscreens comes from a groundbreaking study released in 2011 by the Environmental Working Group (EWG). They analyzed nearly 400 peer-reviewed studies of the 17 sunscreen chemicals approved for use in the U.S. which included an analysis of sunscreen ingredient toxicity linked to 60 industry and government databases on chemical hazards, coupled with customized, product-by-product assessments of protection from both UVA and UVB radiation. And, not to rub it in, sunscreens may have a role in promoting Vitamin D deficiency, depression such as seasonal affective disorder (SAD) and even cancer.2

To help you make sense of why sunscreens are controversial and why they are here in the first place, here’s a brief ‘Sunscreen Primer’ – “You Can’t Follow the Game without a Scorecard.” 

Solar exposure causes premature aging and at worst, skin cancer. The International Agency for Research on Cancer of the World Health Organization classifies all categories and wavelengths of ultraviolet radiation as a Group 1 carcinogen.  This is the highest-level designation for carcinogens and means, "There is enough evidence to conclude that it can cause cancer in humans".3,4

The sun gives off ultraviolet (UV) radiation in the UVA, UVB, and UVC bands. The Earth's ozone layer blocks 97-99% of UV radiation.  However, the two to three percent of radiation that the earth receives has both helpful and harmful effects. You can also receive UV radiation from sun lamps and tanning booths.5

UVA and UVB account for 90% of the symptoms of premature skin aging, including wrinkles. UVC radiation is mostly screened out by the earth’s atmosphere. UVA, though not as powerful as UVB, penetrates deeper into the skin, is responsible for photo damage and increases the risk of malignant melanoma, the most dangerous form of skin cancer.  UVB primarily affects the skin’s outer layers, causing skin to darken and burn and UVB increases the risk of basal cell carcinoma and squamous cell carcinoma, two forms of non-melanoma skin cancer.6

There are two general types of sunscreens.

Physical sunscreens or “sun blocks”  use physical UV filters, while chemical sunscreens or “sunscreens” use chemical UV filters. Most formulations contain both chemical and physical UV filters.

Sun Block - Physical (or inorganic) sun blocks protect your skin from the sun by deflecting or blocking the sun's rays.  The inorganic sunscreens are insoluble particles that reflect UV away from the skin, such as zinc oxide or titanium oxide.  Particle size of the UV filters and overall product formulation determine how much protection you receive from these types of sun blocks.  Zinc oxide and titanium dioxide are helpful in protecting against UVB and UVA rays, but not the full spectrum of UVA rays.  They are extremely photostable, meaning that they don’t break down and stop working when exposed to UV radiation.  The problem with physical sun blocks is that they are typically thick and opaque and can be hard to apply.  Have you seen beach lifeguards walking around with white noses?  That’s physical sun block.  In recent years, researchers have worked to reduce physical sun blocks to nanoparticle size so they are easier to use and less noticeable.

Sunscreen - Chemical sunscreens work by absorbing the sun's rays.  They form a thin, protective film on the surface of the skin and absorb the UV radiation before it penetrates the skin.  Chemical sunscreens can contain any number of UV light absorbers such as avobenzene, octylcrylene, octinoxate, octisalate, oxybenzone and more.  Chemical filters offer more coverage against UVA and UVB rays than physical sunscreens.

Avobenzone, for example, protects against the full spectrum UVA rays.  However, avobenzone breaks down quickly when exposed to sunlight unless mixed with other chemicals.  Chemical sunscreens are typically colorless and odorless with a thinner consistency, though manufacturer’s preparation may change the thickness and smell.  While generally safe, some chemical filters generate free radicals, which can make your skin age and some can also cause allergic reactions.

What's SPF - Sunburn Protective Factor) and PPD - Persistent Pigment Darkening?

SPF is a measure of how much solar energy (UV radiation) is required to produce sunburn on protected skin versus the amount of solar energy necessary to produce sunburn on unprotected skin. Keep in mind that the SPF is for UVB rays only.  As the SPF value increases, sunburn protection increases.  You can buy products that range from an SPF of 8 to as much as SPF 100.

Many people erroneously believe that if you double the SPF factor, you double your protection, but that’s just not true. According to the American College of Dermatology,  a SPF 15 product blocks about 94% of UVB rays, a SPF 30 product blocks 97% of UVB rays, and a SPF 45 product blocks about 98% of rays. Sunscreens with higher SPF ratings block slightly more UVB rays, but none offers 100% protection.  Researchers say that SPF 15 sunscreens are fine if used correctly, but they usually recommend SPF 30 products because few people apply sunscreens as heavily or as often as they should.7

By the way, many people believe that SPF relates to time of solar exposure.  Not true!  SPF is related to the amount of solar exposure, not the time.  Although solar energy amount is related to solar exposure time, factors such as the intensity of the sun, skin type, amount of sunscreen applied and reapplication also influence protection.  

PPD (persistent pigment darkening) measures how well a sunscreen protects against UVA rays.  Therefore, SPF will help prevent sunburns, while PPD guards against photo-aging.  PPD has a numerical value and the higher the number, the better the UVA protection it offers.  However, there is no international standard for measuring how well UV filters protect against UVA rays, so the way PPD values are determined may differ from company to company and country to country.  Because of lack of consistency in measurement, PPD values can only be estimated.  Some sunscreens don’t even have PPD written on their label. If they do, PPD values of 8 or higher are recommended.

So, what’s the problem with sunscreens and sun blocks?

Inadequate Protection - The EWG study found that 84 percent of 785 sunscreen products with an SPF rating of 15 or higher offer inadequate protection from the sun’s harmful rays, or contain ingredients with safety concerns. For example, some popular sunscreen chemicals break down when exposed to sunlight and must be formulated with stabilizing chemicals while others penetrate the skin and present significant health concerns. And remember, about 20% of sunscreen products are not broad-spectrum - UVA and UVB.

Application and Frequency - Studies examining how people use sunscreen/block have noted that most people do not apply a thick enough layer to receive the full benefit of the SPF factor.  The average person needs about one ounce of sunscreen — enough to fill a shot glass — to cover the body.  Most people use only one-quarter to one-half that amount. They also do not apply protection often enough.  For example, if you are perspiring heavily or swimming, you need to apply protection much more frequently; there is no such thing as a waterproof product.8

Vitamin D Deficiency - Sunburn-causing UVB wavelengths that sunscreens are designed to block also start the chemical reaction in your body that produces vitamin D. Extensive use of sunblock reduces the amount of helpful UVB our bodies absorb creating the potential for vitamin D deficiency. And research shows that 36-57% of the U.S. population is already vitamin D deficient.9 

It is nearly impossible to get enough vitamin D from food.  Sunlight exposure is the only reliable way to get your body to produce it. Some researchers say that we need about 20 to 30 minutes of exposure daily to generate enough Vitamin D. They recommend getting out in the sunlight unprotected before 10am and after 4pm to receive the benefits of UVB rays while minimizing any damage. It would take ten glasses of Vitamin D-fortified milk to get the minimum amount of Vitamin D required each day.

Vitamin D may also help prevent osteoporosis, depression, prostate cancer, breast cancer, and even affects diabetes and obesity.  Researchers are also discovering that vitamin D promotes normal cell growth and is fundamental for maintaining hormonal balance and a strong immune system.

Depression - Research also suggests that light hitting your skin and eyes, helps reverse Seasonal Affective Disorder (SAD), which is caused by a melatonin imbalance initiated by lack of exposure to sunlight.  Melatonin is a mood-regulating hormone.  It helps control your daily rhythms, waking you up in the morning and bringing you down at night.  Blocking too much sunlight can prolong SAD.

Vitamin A Additive The Environmental Working Group determined that Vitamin A, often in the form retinyl palmitate, is frequently added to sunscreen/block products. Vitamin A may increase your odds of skin cancer.  Recent FDA data indicates that forms of Vitamin A can be photo carcinogenic.  Combined with the sun's UV rays, they can cause changes in your skin, which may form cancer.  About 30% of sunscreens contain retinyl palmitate and should be avoided due to these and other medical concerns. However, in August 2010, commentary published in the Journal of the American Academy Dermatology claims that retinyl palmitate is safe in sunscreens.10,11

Other Chemical Additives - Sunscreen/block products can contain a variety of chemicals.

  • PABA: Though uncommon now in skin preparations, forty percent of the population is sensitive to it, experiencing red, itchy skin.
  • Benzophenone (benzophenone-3), homosalate, octy-methoxycinnamate (octinoxate) and parabens may function like human estrogens and disrupt the normal hormonal functioning of the body including the lowering of testosterone levels in males.
  • Padimate-O and Parsol 1789 (2-ethylhexyl-4-dimethylaminobenzoic acid and avobenzone): These two chemicals have the potential to damage DNA when illuminated with sunlight.

OK, so what’s being done to help clarify the sunscreen controversy?

Sunscreen/block makers dispute the EWG study’s findings saying they tested the ingredients individually, rather than in the combinations created by the manufacturers.

However, in July 2011, after many years, some say 33, the U.S. FDA finally weighed in on this issue with the publication of new labeling regulations.12

  • New sunscreen labels will allow products to claim "broad spectrum" protection only if they pass specific FDA tests for blocking UVA rays, and if they have an SPF value of at least 15.  Products that earn the "broad spectrum" label will protect people from 90% of UVA radiation.
  • Products that don't protect against UVA, or which have an SPF of less than 15, will have to carry a warning, noting that they don't protect against skin cancer.
  • Sunscreens will also carry a "drug facts" box that provides more detailed information about sun protection.
  • Sunscreens will no longer be allowed to market themselves as "sun block," "sweat proof" or "water proof."  Instead, sunscreens will be allowed to say only whether they are "water resistant" for either 40 minutes or 80 minutes.
  • FDA would also bar sunscreens from claiming SPF values above 50, because there is no way to scientifically prove these claims.  Instead, sunscreens will be allowed to claim only that products are "SPF 50+."

The Bottom Line 

We have all been burned at least once. Either you limit your sun exposure to 20 minutes or you use sunscreen for longer exposure. But, sunscreens remain controversial...

If you believe that sunscreens are beneficial and outweigh the risks, check out the following sources...A Guide to the Best Mineral SuncreensSafeMama  and the Environmental Working Group’s Guide to Sunscreens. Check the label for chemicals to avoid and select a product that won’t irritate your skin. For example you may need to test products with various levels of alcohol content.

Apply products 15-30 minutes before sun exposure, even on cloudy days. Apply a thick, even layer of product to all exposed areas.  Don’t forget your ears, neck and backs of legs. Sunscreen goes on after moisturizer and other skin treatments (wait 30 minutes) but before makeup.  If you don't wear any makeup, sunscreen should be the last thing you put on your skin. Reapply sunscreen every 2 hours, especially if it is an unstable sunscreen.

If you are still not convinced that there is a safe sunscreen, limit your sun exposure, but never forget that we still need some sun exposure especially when it comes to Vit D. Then again you could take D supplements. 

"Truth is like the sun. You can shut it out for a time, but it ain't goin' away" - Elvis Presley.

Published August 16, 2011, updated June 22, 2014


References

  1. What are the key statistics about melanoma, American Cancer Society
  2. EWG’s Skin Deep - Sunscreens 2012  
  3. Aurier P, Carcinogenic to Humans: Why the International Agency for Research on Cancer Added Indoor Ultraviolet (UV) Tanning to Group I, The Melanoma Letter Summer 2010 Vol. 28, No. 2
  4. Matsumura Y,  Toxic effects of ultraviolet radiation on the skin, Toxicol Appl Pharmacol. 2004 Mar 15;195(3):298-308
  5. Nations Unite Against Tanning: The Impact of the IARC Report, The Melanoma Letter Summer 2010 Vol. 28, No. 2
  6. Brannon H, Effects of Sun on the Skin, Dermatology, About.com, March 23, 2007 
  7. Bromberg M, Sun Screen,What we need to know about SPF,  Better Quality Buzz, May 11, 2011
  8. Wear Sunscreen the Right Way, Skinacea
  9. Holick MF,  High Prevalence of Vitamin D Inadequacy and Implications for Health,  Mayo Clin Proc. 2006 Mar;81(3):353-73.
  10. Lunder S, What Scientists Say about Vitamin A in Sunscreen,  Environmental Working Group, June 20, 2011
  11. Analysis finds Sunscreens containing Retinyl Palmitate do not cause Skin Cancer, American Academy of Dermatology, PR Newswire, August 10, 2010
  12. Szabo L,  FDA announces stricter sunscreen rules,  USA Today, June 14, 2011

Susan M. Brissette brings 30 years of experience in healthcare, ranging from positions as Chief Executive Officer and Chief Operating Officer in the acute care hospital setting to Senior Executive for a major national healthcare management company. Ms. Brissette holds a BS in Biology from Northeastern University and an MS in Health Policy & Management from the Harvard School of Public Health. She has lectured on healthcare management at the University of Massachusetts, developed a healthcare delivery system for a mining company in Cajamarca, Peru, and recently led the Afghanistan Public Health Redevelopment Task Force for the Washington Harvard Alumni Group. She has consulted on healthcare projects in Poland, Romania, Israel, Kuwait, Peru, Canada, and Mexico. She now owns and operates SB Cass Associates, a healthcare consulting firm located in upstate New York. Ms. Brissette’s consulting practice handles client projects ranging from business plan development for clinics, assisted living facilities, and clinical research groups to the development of market research reports for the pharmaceutical and biotechnology industries. She has written dozens of healthcare articles published on the internet and in national professional and consumer journals. She has also authored or edited online courses on HIPAA compliance, corporate security, childhood obesity, and business ethics.

Susan Brissette can be reached at SB Cass Associates [email protected]

Introducing Stitches!

Your Path to Meaningful Connections in the World of Health and Medicine
Connect, Collaborate, and Engage!

Coming Soon - Stitches, the innovative chat app from the creators of HWN. Join meaningful conversations on health and medical topics. Share text, images, and videos seamlessly. Connect directly within HWN's topic pages and articles.


Be the first to know when Stitches starts accepting users


The Latest from Heads or Tails

Obamacare, is it on Life Support?
Obamacare, is it on Life Support?

If Obamacare is so wonderful, why is it that its loudest advocates don't want to be subject to it - Ted Cruz

If You Think 'Organic' Food is 'Organic', Think Again
If You Think 'Organic' Food is 'Organic', Think Again

The organic food industry has outgrown the original regulations meant to protect it and its consumers. How 'organic is organic food' is even more important now than in the past

ObamaCare, Is There a Fix?
ObamaCare, Is There a Fix?

It’s not defunding ObamaCare or granting everyone the current ‘federal worker option’ or even socialized medicine. Just ask our neighbors, the Canadians

Stay Connected

Health Cloud