Broad Spectrum Sunscreen: Do You Need to Wear it Every Day?

Cynthia Bailey, MD|May 19, 2014

As the weather warms up it’s tempting to go outside to soak up the welcomed warmth of the sun. Is it okay? Can you get away with letting your guard down, throwing caution to the wind, and going out in the sun au natural? You may want to, heck, I do. I hear the rationalizations all the time, that

  • a little sun exposure every day is healthy
  • the “base tan” protects skin from sun damage
  • daily sun exposure is necessary to keep up a healthy vitamin D level

But, soaking up any amount of UV rays is not so innocuous for your skin.

What I've seen during years of skin exams says otherwise. Patient after patient, I see that the areas of skin that are exposed to the sun every day are thin, wrinkled, fragile, and mottled with sun spots.

We've known for years that exposure to the sunburn ray (UV-B) breaks down skin structure (aka causes wrinkles), but now, according to the results of a new study, we now have proof that daily sun exposure to the more common UV-A1 ray will breakdown the structure of your skin too. And, many sunscreens are not that good at protecting you from UV-A1 - so, keep reading, this is important! In a new study just published in JAMA Dermatology, study investigators showed that even low-dose repeated exposure of fair skin to UV-A1 rays caused a gene to be activated that actually breaks down your skin’s collagen. Yes, you have a gene in your skin that breaks down your collagen. It's a sadly efficient way of making your skin look old. That gene is activated by UV light. Study investigators have proven that UV-A1 exposure, just like UV-B exposure, turns on the gene. Once turned on, it becomes a self-perpetuating cycle of collagen degradation!  The end result is skin that is:

  • thin
  • fragile
  • wrinkled
  • easily torn

Yes, the cycle keeps on going, but more UV exposure means greater collagen breakdown. A tan does not protect your skin from collagen breakdown from UV sun exposure. In the study, the fair skin of the volunteers did tan from the UV-A1 exposure and that tan did not protect the skin from this gene activation. Read that again, tanning DID NOT stop the gene activation. Translated another way, this debunks two common myths about tans:

  • Tanning Myth #1: A “base tan” protects your skin from damage.
  • Tanning Myth #2: A tanning bed tan is sun protection before you get "real" sun exposure.

So, we have known for years that sun damage  (aka “photo-aging”) of your skin happens when it is exposed to UVB rays (the midday summer sunburn ray). We now have proof that the same type of photo-aging happens when your skin is exposed to UVA.  Most of UVA is UV-A1. The difference between UV-B and UV-A1 is more important than you might think. Why are UV-A1 rays so important? UV-A1 rays are important because they:

  • are the most intense UV sun ray and they are intense all day long and all year long.
  • come through window glass.
  • are not blocked very well by many sunscreens.

There are only two sunscreen ingredients that are FDA approved to block UV-A1. Be sure your sunscreen contains one of these two ingredients! The rest of the sunscreen ingredients listed on the back label of a product block UV-B and some block into UV-A2, but they don’t do a good enough job blocking UV-A1, which is why they are not FDA didn't approve them as such. The two FDA-approved sunscreen ingredients that block UV-A1 are:

  • zinc oxide (all of our sunscreens contain zinc oxide - and they always have because I could see the difference on my patients' skin when they used a zinc oxide sunscreen)
  • avobenzone (a fragile sunscreen ingredient that I’m not a fan of and that, in my observations, does not work well).
The bottom line is that your skin will look much younger when you wear a sunscreen that blocks both UV-B all the way through UV-A2 and into UV-A1.  Wear this sunscreen on all of your sun-exposed skin everyday. In my opinion, zinc oxide mineral sunscreens are the best sunscreens.

What do you have to gain when you wear a zinc oxide broad spectrum sunscreen every day? You will be fending off:

  • wrinkles
  • skin thinning
  • age spots
  • “farmer’s neck”
  • those purple blotches (actinic purpura) and skin tears that happen on the outer arm skin after many years of sun exposure
  • thin skin on the back of your hands that lets your veins show through almost transparently
  • the ruddy brown discoloration that occurs on the sides of your neck over the years (poikiloderma of Civatte)
  • wrinkles between your breasts (women only)

... and that's just the collagen degradation list! I recommend that you use a hat and sun-protective clothing too.

Love your products Dr!”   Monica S, NYC, NY

Are you feeling frustrated because of all the years of sun exposure that you can’t erase? There’s hope. Wear a zinc oxide sunscreen to stop new damage and use a retinoid as a night cream. Retinoids can stop the self-perpetuating cycle of collagen breakdown by the metalloproteinase genes (read below) from those UV “sins of the past”. Broad Spectrum Sunscreen & Retinol Intensive reverse sun damage Yes, it’s true. Retinoids, such as tretinoin (in prescription Retin A and Renova) and all-trans-retinol (in our non-prescription Retinol Intensive Anti-Wrinkle Night Creams) have been scientifically proven (visit the product page for the scientific references) to halt the collagen breakdown cascade. In my opinion, the combination of a zinc oxide broad spectrum sunscreen during the day and a retinoid product at night is the best anti-aging skin care you can use.   Need a facial broad spectrum zinc oxide sunscreen?

 

Here's my Quick Pick Broad Spectrum Sunscreen Facial Guide

Suntegrity 5 in 1 Natural Moisturizing Face SunscreenSuntegrity 5 in 1 BB Cream SPF 30 tinted and moisturizing sunscreen for dry/normal skin         best sunscreen for oily skin mdsolarsciencesMDSolarSciences SPF 30 tinted and mattifying sunscreen for oily skin         Elta MD UV Clear SPF 46EltaMD Clear SPF 46 untinted and lightweight facial sunscreen for oily/normal skin         dermatologist recommended broad spectrum mineral zinc oxide sunscreen for all skin typesCitrix SPF 40 sunscreen for neck/chest/ears/hands/arms/legs. Trusted water-resistant protection that’s invisible and easy to use.         Elta Lip Balm SPF 31 sunscreenEltaMD Lip Balm SPF 31 sunscreen lip protection         Because you'll be sooooo very surprised to find UV rays in places you least expected them, I recommend you try out these UV-sensing beads to up your sun-exposure knowledge. uv detecting beads UV Detecto Ring      

I am a dedicated reader of your blog and my skin is better for it.   Paul B

For we skin care and science geeks who want details the story goes on ... If you’re like me and you like to know how things work, this study is fascinating. It shows that UV-A1 triggers gene activation of matrix metalloproteinase 1, which starts the cascade of collagen breakdown. We've know that even a little exposure to UVB (mid-day sun burn ray) causes gene activation of collagen breakdown via metalloproteinases. UVB also suppresses collagen synthesis – a double whammy for skin collagen loss and wrinkling. It’s been less clear what exactly happens from exposure to the sun’s UVA rays, which are 10-100 times more intense than UVB rays AND are not blocked well by many sunscreens. UVA also sneaks through when you think you’re protected because it penetrates windows and some fabric. UVA rays are longer than UVB rays, which allows them to penetrate much deeper into your skin than UVB - creating an even more widespread structural and cancer-causing damage than UVB. UVA is broken down into UV-A2 and UV-A1. UV-A2 rays have 320-340nm of distance between wave peaks which means they are more similar/closer to UVB than UV-A1. UV-A1 rays are 340-400nm long between wave peaks making them the longest of the UV rays. 75% of the sun’s UVA rays are UV-A1. These rays are the most deeply skin-penetrating UV ray, the least well blocked UV ray by sunscreens, and the main ray in tanning beds. UV-A1 rays, with their longer wave lengths, are sort of the “Holy Grail” UV ray. In this study, fair-skinned volunteers had their sun-protected buttocks skin exposed to UV-A1 rays and the impact on their skin was measured. The study investigators chose to use a low-dose UV-A1 to mimic what you would expect from a 2-hour exposure to real sun. They exposed the same area of skin daily for up to four days and then tested the skin. They found that this repeated exposure to UV-A1 damaged the structure of the skin in spite of skin tanning. This means that a tan does not protect you from sun damage. Bottom line:  UV exposure in preparation for a sunny vacation does not protect you from wrinkles. Said another way, UV exposure = wrinkles, tan or no tan. Again, the FDA has approved only two broad spectrum sunscreen agents as adequate for UV-A1 protection. They are zinc oxide and avobenzone. I only recommend zinc oxide for true broad spectrum sun protection due to the fragility of avobenzone, which readily breaks down upon contact with UV rays and even with other ingredients in a sunscreen formulation. Zinc oxide is also gentler to sensitive skin. The FDA has approved a number of other sunscreen ingredients as protection from UV-B and UV-A2.  Outside of the U.S. there are some other UV-A1 chemical sunscreen ingredients that work well at blocking UV-A1.  I still prefer the physical mechanism of using zinc particles to bounce UV rays off the surface of your skin rather than chemical ingredients that stop rays with a chemical reaction that occurs at the level of your skin. In my opinion, you need a broad spectrum sunscreen with zinc oxide. The concentration of zinc oxide should clearly be labeled as 5% or higher. You should wear it every day on exposed skin to prevent wrinkling, thinning, and the gradual skin fragility that comes from daily sun exposure, even sun exposure through window glass. For more of my practical sun protection advice to help keep your skin healthy and attractive, please take a look at my posts listed below. If you have found these broad spectrum sunscreen tips helpful, please show your thanks by commenting on, sharing, “liking,” Google+, tweeting, and “pinning,” using the social sharing buttons above and below this blog post with friends and family. Sincerely, Dr. Bailey Skin Care Team

 

Broad Spectrum Sunscreen Reference:

Dermal Damage Promoted by Repeated Low-Level UV-A1 Exposure Despite Tanning Response in Human Skin, Frank Wang, MD; Noah R. Smith, MD et. al., JAMA Dermatol. 2014;150(4):401-406.   Photo attribution: Thanks and gratitude to © Ian Lishman/Juice Images/Corbis and © Andrew Plewes/ImageZoo/Corbis