My husband often accuses me of being a vampire as I loathe being in the sun. But perhaps I should clarify that I do enjoy the life and light giving sun, just not the sunburn or inevitable sun damage. My beach time is between 8-10AM and 5PM until dark thirty. And truly, those hours are the best (and least crowded) on the beach. The following post details my thoughts on sunscreen and sun protection. It begins with the summary and then dives deeper for those who want to know more.
Summer is upon us — the season of suntans and sunburns. While most people recognize the dangers of sunburns, many do not understand, that a tan is an injury response in skin. It is sun damage. The light energy emitted by the sun is called electromagnetic radiation. This spectrum includes visible light as well as invisible forms such as radiowaves, microwaves, infrared heat energy, ultraviolet radiation (UVR), X-rays and gamma rays. It is the invisible ultraviolet light/radiation that causes suntans, sunburns, skin cancers, and 90% of what is recognized as aging in the skin. (Check out this video for a more detailed introduction on “light.”)
Photoprotection (or sun protection) is the most important preventive strategy against skin cancer. Photoprotective strategies include seeking shade and avoiding the sun during the peak hours of the day (10AM to 4PM), wearing long-sleeved shirts, wide-brimmed hats and sunglasses, and applying and then reapplying sunscreen. Ideally, sunscreen should be used only on those areas that one cannot cover with clothing and not as the only part of a photoprotection plan. Protection is also needed on cloudy days as up to 80% of the UVR emitted by the sun can penetrate clouds.
RRD Tips for Sun Protection
The sun produces both visible and invisible rays. The invisible rays known as UVA (Ultraviolet A) and UVB (Ultraviolet B) cause suntan, sunburn, and sun damage. For simplicity: UVA contributes more to AGING skin and UVB is the cause of BURNS. They both contribute to tanning and to skin cancer formation. A third type of UV light (UVC) does not penetrate Earth’s atmosphere, but it can be produced artificially and is used to kills germs. In short, there is no “safe” UV light. Therefore, using sun protection and avoiding artificial sources of UV light (i.e., tanning beds) can help prevent skin damage, wrinkles, and reduce the risk of skin cancer.
- SUNSCREEN: Use a broad-spectrum sunscreen (that protects against both UVA and UVB) with an SPF of at least 30 on all sun exposed skin, including the lips, even on cloudy days.
- If exposed to water, either through swimming or sweating, a water-resistant sunscreen should be used.
- Apply sunscreen at least 15 minutes before sun exposure.
- Reapply sunscreen frequently — every 1½- 2 hours, more often if sunny or heavily perspiring.
- Consider a double application as most people do not apply the recommended amount of sunscreen.
- SUN PROTECTIVE CLOTHING:
- The most cost effective item for sun protection is a wide-brimmed hat.
- Wear sunglasses to protect the delicate eyelid skin and to protect against cataracts.
- Wear protective long sleeves. Darker colors and tighter weaves offer more protection than loose weave light colored fabrics. In humid Louisiana, breathability in a fabric is also important, so I tend to wear loose weaves daily and breathable tighter weaves for the beach and outdoor exercise. Here are a few of many sites for beach and fishing wear: coolibar.com, simmsfishing.com, cabanalife.com, mott50.com.
- Tinosorb (Rit SunGuard) is a laundry additive that can increase the UV protection in the clothes you already own for up to 20 washings.
- Breathable and lightweight UPF fabrics such as “Buffs” can be used to protect the neck and chest and can be easily pulled over the face and ears. Lightweight “sleeves” can be used to cover the legs for those who prefer short-sleeved shirts and shorts.
- Wear “sun gloves” when fishing.
- Consider using a topical antioxidant (Vitamin C, Vitamin E, ferulic acid, green tea polyphenols, idebenone, etc…) in the morning under sunscreen. Many sunscreens now offer functional antioxidants in their formulations. Caveat emptor: make sure the company provides data that the antioxidant is playing an active role in photoprotection and is not just in the product as a stabilizer.
- If you plan to spend a lot of time outdoors, consider a polypodium leucotomos supplement (an oral antioxidant that has been shown to be protective against UV damage) like Heliocare or Drink UVO.
- OUTSIDE PRECAUTIONS:
- Seek shade whenever possible.
- Plan outdoors activities early or late in the day to avoid peak sunlight hours between 10 AM and 4 PM when the sun’s rays are strongest.
A Detailed Look at Sunscreens
Sunscreens are topically applied agents used to filter (or screen) ultraviolet radiation (UVR). To work properly, they must form a continuous film on the skin. This film must stay intact for the sunscreen to provide the SPF listed on the label. Sweat, heat, oil production, water, or friction can poke holes in this film. Hence reapplication is a must for extended exposures. Sunscreens should be applied 15-30 minutes prior to exposure to allow time for this film to bind to the skin. No single sunscreen ingredient can filter 100% of the UVR spectrum, so most sunscreens are a combination of minerals that reflect or chemicals that absorb UV light.
What’s in a Sunscreen? Decoding the Label
Minimum standard: 2 ingredients to ensure a broad range of filtering ability.
To effectively filter both ultraviolet A (UVA) and ultraviolet B (UVB) rays, most sunscreen products use more than one active ingredient as no one ingredient can filter 100% of the UV rays. There are two broad classifications of sunscreens: organic (AKA: chemical) and inorganic (AKA: physical or mineral). Many sunscreens combine both classes. Additionally, some sunscreen filters are easily broken down by UV light and require combination with photo-stabilizers to remain effective.
Organic sunscreens refer to those chemical compounds that contain chains of carbon atoms and not those that are USDA certified organic. Organic UVA blockers include avobenzone, oxybenzone, and ecamsule. Avobenzone requires photo-stabilizers and is marketed as Parsol 1789 and as Helioplex (complexed with oxybenzone). Organic UVB blockers include cinnamates like octinoxate and octylcrylene, salicylates like octilsalate and anthralinates. Oxybenzone filters both short wave UVA and UVB. These sunscreens work by absorbing UV light and converting it to heat.
Inorganic sunscreens are minerals/metals such as zinc oxide and titanium dioxide. They provide sun protection by reflection and scatter of UV light. Higher concentrations of micronized zinc oxide can provide broad spectrum coverage and be used as a solo ingredient in some formulations.
In the US, sunscreens are classified as drugs (as opposed to cosmetics) and must be FDA-approved. No new ingredients have been approved in over 10 years.
SPF = Sun Protection Factor
Minimum Standard: SPF 15-30 for daily use.
The SPF or Sun Protection Factor is a measure of a sunscreen’s ability to filter UVB light and thus prevent burns and skin cancer. It is not an indicator of a sunscreen’s ability to protect against UVA – the primary cause of aging skin and a contributor to skin cancer. Additionally, higher SPFs may not necessarily offer much more protection as an SPF of 15 blocks 93% of ultraviolet radiation (UVR) while SPF 30 blocks 97% and an SPF 50 98%. In short, an SPF 30 is not double the protection of SPF 15. In real world conditions, however, most people are not receiving the SPF on the bottle because they do not apply enough sunscreen.
The recommended amount of sunscreen to use is 2mg/cm2. This translates to 1 ounce of sunscreen to cover the body not covered by a swim suit. In studies of how sunscreen is applied in the real world, most people apply closer to 0.5 to 1mg/cm2 or ¼ to ½ of the recommended amount. SPF is based upon a logarithmic scale, so choosing a higher SPF, say SPF 70, and only applying one half of the recommended amount does not yield an SPF 35, but rather an SPF closer to 8. (To calculate the SPF of a “half” application (1mg/cm2) take the square root of the SPF on the bottle). To combat this, consider a double application to achieve correct sunscreen thickness and thus the actual SPF on the bottle. This is especially important for outdoor activities.
Minimum Standard: Broad Spectrum should be listed clearly on the label.
For US sunscreens, the term broad spectrum means that a product can adequately filter both UVA and UVB.
Minimum Standard: 40 minutes for intense UV exposure. Water resistance is not required for daily use of minimum exposure.
Sunscreens can no longer claim to be “sweat proof” or waterproof”. The FDA rates sunscreens as water resistant for 40 or 80 minutes based upon standardized testing in wet conditions. For intense sun exposure and swimming, a water-resistant formula is required. You must reapply every 40 or 80 minutes (depending on the formulation chosen) to receive the SPF reported by the label.
For more information check out the Skin Cancer Foundation Guide to Sunscreens.
Do you have more questions about sunscreens or photoprotection? Stay tuned over the next few weeks as we explore how to choose a sunscreen and how to survive a sunburn.
Do you have a suspicious spot? Contact us at Red River Dermatology at 318-442-9395 to schedule a skin check and to discuss prevention and treatment strategies.