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:
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.
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?
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.
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.
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. Manufacturers must make the following changes by the summer of 2012.12
The Bottom Line
If you believe that the current sunscreens are beneficial and outweigh the risks, choose a product that is broad-spectrum with an SPF of at least 30 with a PPD of at least 8. However, check the label for chemicals to avoid and select a product that won’t irritate your skin. You may need to test products with various levels of alcohol content, for example. And, visit the Environmental Working Group’s Guide to Sunscreens and view their “Hall of Fame “and “Hall of Shame.” The July 2010 issue of Consumer Reports also rates sunscreen products.
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.
But, if you believe sunscreens may cause more harm than good, then don’t use them or check out some of the ‘natural’ sunscreens.
Published August 16, 2011, updated April 14, 2014
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@example.com