UVA versus UVB rays

Incredibly telling image of a gentleman whose profession from trucking. The left side of his face which was exposed to the window and sun show extreme signs of photoaging compared to the right side.

Do you want people to look at you and say ‘You’re aging so gracefully’, Umm YES! At 40, do you still want to look like you did in your younger 30s? Duh. There is only 1 skincare product that’s going to allow you to achieve that result. SUNSCREEN. And we’re discussing this as we approach the winter months when sunburn is generally the least of our worries. What am I thinking??

This is a great background from @theYesStylist and anything I produce isn’t going to be an improvement. UVB is the burning ray, UVA is the aging ray.

For UVB you do need to protect it with sunscreen that has an SPF rating. Most people are use to the SPF rating. Dermatologists recommend an SPF of at least 30. I disagree and agree at the same time. The amount of sunscreen needed to reach the FULL SPF is around 1/2 a teaspoon for the face and neck. The VAAAAAST majority of people only apply 25% of that amount if that much (Gonzaga, 2009). Foundation is not an effective delivery for sunscreen, you do need a dedicated sunscreen. As such you’re getting the equivalent of an SPF 7.5 if you apply 25% SPF 30. If you go in with an SPF 50 you end up with an effective SPF of around SPF 12.5. The reason this is so important is there is an exponential growth in protection between an SPF0 to around SPF15.

SPF 0 = 0
SPF 2 = 50%
SPF 4 = 75%
SPF 10 = 90%
SPF 15 = 93.3%
SPF 30 = 96.6%
SPF 50 = 98.3%

These numbers don’t correlate to the percent of UVB blocked, which from a consumer standpoint makes a lot more sense. Enter the PA scale.

For UVA, in the US we look for the term ‘Broad Spectrum’ which means both UVA and UVB protection. Especially in Asia ,you’ll see PA with a series of ‘+‘. Personally, I prefer this one to the vague term broad spectrum. The scale also correlates to the Persistent Pigment Darkening, which is how long it takes the skin to tan.

PA+ = Some UVA protection/ 2x time to tan
PA++ = Moderate UVA protection / 4x time to tan
PA+++ = High UVA protection/ 8x time to tan
PA++++ = Extremely High UVA protection/ 16x time to tan

The PA system was developed in 2013 and was developed in Japan. It’s become such a popular system that instead of making a dual packaging system some companies are presenting both the PA and SPF sunscreen ratings on their packaging outside of Asia.

From an overall skin health perspective look for sunscreen that has both UVA and UVB protection. It’s rather difficult to find one that doesn’t offer both today now that we know the importance of BOTH UVA and UVB rays. At this time there are only two true broadspectrum active ingredients: Zinc oxide and Avobenzone.

,Zinc Oxide has been a popular sunscreen choice for a few years now. Titanium oxide, although popular sunscreen choice, offers less UVA protection than zinc oxide. If you have a choice, Zinc oxide is a better sunscreen choice (Beasley and Meyer, 2010). Those two chemicals encompass the mineral sunscreens. My favorite right now is Supergoop!’s Zinc Screen which I bought at Sephora.

For synthetic sunscreens, avobenzone is the only sunscreen with high UVA/UVB ratings ( Beasley and Meyer, 2010 ). There is some questions regarding the safety of avobenzone. It does breakdown quickly which means you have to reapply every hour instead of every two. There are also concerns that the breakdown products may be cancer causing but those concerns are based on some interesting science (but that’s how almost all major findings start in medical science, ‘oh that doesn’t look right’; Damiani et al, 1999). There’s also data that shows avobenzone could be used to fight cancer (Pettenari et al, 2016). Avobenzone continues to be the gold standard for synthetic sunscreen protection (Gonzaga, 2009) and gets a low risk score of 1-2 from EWG if you follow their guidelines.

Even during the winter months we need to be wearing sunscreen since aging UVA rays which make up 98% of the UV exposure are still present. Plus you can get sunburn in February, I am living proof of it.

Hopefully this has helped declutter what UVA and UVB is and the PA rating scale. When I'm asked for the one product to start a skin care routine I will always tell people that a good cleanser and sunscreen is an absolute must. A good cleanser is used twice and day and can keep the acne away but sunscreen is a daily activity that will affect the fate of your skin 20, 30, 40, 50, 60 years down the road. Those people who have the best looking skin in their 50s and 60s were habitual users of sunscreen or avoided the sun all together. Like so many 20 somethings I didn't and I'm paying the price now with sun damage, concentrated around my ears, hairline, nose, and cheekbone area. If you look at every influencer in their later 20s and older, every single person discusses dark spots they're treating. It's caused by sun damage and lack of proper sunscreen usage.

Stay gorgeous.



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