Let’s talk about protecting our skin from the sun. A lot of people think, ” I don’t spend a lot of time in the sun.” But that’s just not true. You don’t have to be at the beach or sunbathing or even outdoors to be “spending time in the sun.” UVA rays can penetrate the windows of your home or car and are doing damage to your skin every day if you’re not wearing a good sunscreen.
Some people believe that if you don’t get a sunburn, you aren’t getting any sun damage. A sunburn is caused by overexposure to UVB rays. But we are exposed daily to the sun’s UVA rays as well. In fact, 95% of solar radiation is UVA. Even on cloudy days, UVA rays get through enough to do damage. Just because you can’t see the sun doesn’t mean you don’t need protection.
Both UVB and UVA rays are linked to skin cancer. And UVA rays are responsible for the majority of the extrinsic aging of the skin. Extrinsic aging is the aging or decline of the skin caused by external factors like sun damage, smoking, diet, etc. If you could prevent or at least slow this decline, wouldn’t you? Not to mention that wearing sunscreen every day can also protect you from skin cancer.
The Lie of SPF
SPF (Sun Protection Factor) is a measure of UVB protection. It doesn’t measure the level of protection from UVA rays. It’s technically a measure of redness.
Moreover, it’s how long you can stay in the sun before getting burned. An SPF 15 means you can stay in the sun fifteen times longer while wearing that sunscreen than you could without it. An SPF 20 means you can stay in the sun twenty times longer. After SPF 30 it stops increasing linearly. So, SPF 100 will not allow you to stay in the sun 100 times longer, for example. Dermatologists recommend wearing a minimum of SPF 30.
In the US, there is not a quantitative UVA rating system like there is for UVB rays. Also, there are newer UVA filters available in other countries that would significantly increase the UVA protection of American sunscreens that the FDA has yet to approve. Mainly it’s because there has been a lot of controversy and debate over UVA testing methods.
So, many sunscreens in the US will protect you from getting burned but not at all or barely from getting sun damage that will cause wrinkles, sagging of the skin, and sunspots.
Some countries do have quantitative UVA rating systems. Japan uses the PA+++ scale, Australia uses the PPD (Persistent Pigment Darkening) scale, and the UK uses the Boots 5-star rating system.
What can you do?
You must be a savvy consumer if you want to truly protect your skin. Currently, the U.S. FDA hasn’t approved more than two substantial UVA filters for use in sunscreens. (There are a couple more approved for use, but they provide only minimal protection in the UVA spectrum.) When you shop for sunscreen you want to look for these two specific UVA-blocking ingredients: Zinc Oxide or Avobenzone.
All sunscreens have to list their “active ingredients” separate from their inert ingredients, so it only takes a couple of seconds to locate and discover what a sunscreen’s “sun blocking” ingredients are. Most sunscreens offer reliable UVB protection so you can just focus on finding these UVA ingredients.
Avobenzone is very photo-unstable, which means it degrades rather quickly in any light. It is easily stabilized in sunscreen formulations, however, by the addition of octocrylene. So, if your sunscreen relies on avobenzone for UVA protection, make sure there is also octocrylene present. Neutrogena’s patented “Helioplex” contains a special ingredient called DEHN that stabilizes avobenzone. Or you may see an ingredient called Solastay (Ethylhexyl Methoxycrylene)—this is also an avobenzone stabilizer.
Zinc Oxide is commonly used at 2-7% concentrations, but you should look for 5% at a minimum with 10-20% being ideal. (25% is the legal maximum. At very high levels zinc-based sunscreens can make the skin appear white unless you can find one that uses nano-zinc oxide or has a tint. Avobenzone is always used at 3%. If it says anything other than 3% you’ll want to avoid it.
Sunscreens that use zinc oxide alone as an active ingredient or zinc oxide and titanium dioxide are physical sunscreens. They are usually better tolerated by those with sensitive skin, and their mechanism of action is to deflect and scatter rays. Any other sunscreen ingredient you see is going to fall under the chemical sunscreen category. These sunscreens work by absorbing the rays. (Note how important it is that you apply an ample amount so that the sunscreen is absorbing the rays and not your skin.) Often sunscreens will be a mix of both chemical and physical active ingredients.
Shame on the FDA
Many sunscreens will say “broad spectrum” on them, but this claim doesn’t mean much in the US right now. It is essential that you check the ingredients.
British researchers looked at US sunscreens that meet the standard for FDA “broad spectrum” protection and estimated that “over a two-week vacation to a tropical latitude, a fair-skinned tourist could successfully prevent sunburn but receive as much UVA exposure as he or she would by visiting a tanning salon ten times–for eight-minute sessions.”
This kind of subpar protection is what you’re getting when you grab any sunscreen with the words “broad-spectrum” on it in the U.S. You can only be confident you’re getting real UVB and UVA protection if you know which UVA-blocking ingredients to look for. It sometimes takes some hunting around, but your skin and your health are worth it. The Environmental Working Group’s website has several recommendations for true broad-spectrum sunscreens. https://www.ewg.org/sunscreen/
Until the U.S. FDA approves these newer UVA filters, the best we can do is to make the most informed consumer decisions possible. Wearing sunglasses, hats and protective clothing, as well as seeking shade whenever possible is especially important when our choices for sun protection are mediocre at best.
If you happen to be visiting Japan, Australia or the UK anytime soon, stock up on sunscreen while you’re there! Look for a high UVA rating in addition to the SPF. You will see active ingredients listed that you don’t see in the U.S.
 Brian L Diffey et al., Suntanning with Sunscreens: A Comparison with Sunbed Tanning. Photodermatology, Photoimmunology & Photomedicine, 2015, 31(6), 307–314.