Wednesday, May 18, 2016

beauty tuesday: how to choose the best sunscreen

Hello everyone! Did you guys know that May is Skin Cancer Awareness month? More than 90% of all types of skin cancer are caused by exposure to the sun, so we want to do everything possible to protect ourselves from what is another cancer that we can possibly prevent. As a medical student interested in ObGyn, I have a very very limited knowledge base about dermatology, so I'm so excited to have Dr. Joyce, who is a dermatology resident at NYU, here today to talk a bit about why sunscreen is so important, and what you should look for when choosing a sunscreen. 
With the sun finally coming out in NYC announcing the long awaited arrival of spring, I have been spending more and more time outside enjoying the rays and getting some vitamin D on my lunch breaks. I use sunscreen daily all year round, but since I'm getting more UV exposure lately, I've been especially vigilant about good sunscreen application and not relying solely on tinted moisturizers or other cosmetics with some SPF. Here's what YOU need to know to protect your skin from skin cancer AND aging this spring.

Why do I need sunscreen?

This is the basic question that I hope I can answer for you today. The sun's rays produce ultraviolet (UV) radiation, invisible waves on the electromagnetic spectrum that cause harm to the skin. UVA radiation causes photoaging, meaning sunspots, wrinkles, leathery, sagging skin (check out this INCREDIBLE photo of sun-induced aging on just half of this truck driver's exposed face here). UVA is the one associated with indoor tanning, and has been found to exacerbate UVB-induced damage as well. UVB radiation, associated with sunburns, causes DNA damage that can result in skin cancers. So the basic reason of why you need sunscreen is that topical application blocks these harmful UV rays from reaching your body and damaging your skin. Think of it as your invisible shield.

How do I choose and apply sunscreen?

Great question! I just made a vlog about this very topic, covering what sunscreens are suited for which skin types - check it out here!
In a nutshell: Dermatologists recommend using a broad spectrum (meaning blocks BOTH UVA and UVB) sunscreen that is at least SPF30. Sunscreen is supposed to be reapplied every 2 hours, but you and I know that that goal is extremely difficult to achieve. I find reapplication difficult because I have makeup on, and it's hard to put greasy sunscreen on over it. My personal philosophy is that if I'm going to be outside for a prolonged period of time in direct sun, I will apply SPF 50 sunscreen over my moisturizer and under my foundation, and wear a broad brimmed hat and large sunglasses. Beyond that, choice of sunscreen is in part a personal decision. Will you be in the water or sweat a lot? Consider using a waterproof sunscreen. Sensitive skin? Look for sunscreen that is fragrance free or consider formulations gentle enough for babies. More on choosing the right sunscreen for your skin type on my blogpost here

Why do I look chalky white with sunscreen?

There are two types of ingredients - physical blockers like zinc oxide and titanium dioxide that offer broad spectrum protection by reflecting the sun's radiation and then chemical blockers like cinnamates and salicylates that block radiation by absorbing it and converting it into heat energy. The caveat about chemical blockers is that they block UVB but need to be combined with other UVA blocking ingredients. The active ingredients in physical blockers can appear chalky and white on application, which I know people don't like! If you fall into this camp, don't despair, Try looking into newer models of sunscreen use micronized ingredients, which reduce the chalky appearance, or choose chemical blockers.

Is sunscreen actually safe to use? I've heard some rumors...

Hold it right there. I have also heard of these reports about the dangers of sunscreen ingredients, and I took a look at the scientific literature to evaluate that myself. What I found is that there is NO good evidence in our research that supports the claim that any ingredients in sunscreens are dangerous. Check out my full report here.

What do you look for in sunscreens?

This could be a whole post! In fact I am going to do a whole series of posts in which I review my favorite and not-so-favorite sunscreens and what I like or don't like about them. The qualities I look for in my sunscreens include:
  • broad spectrum, SPF 30
  • easy to apply, meaning not too chalky and not too greasy
  • mixed with moisturizer because I have super dry skin (I still put moisturizer on first though!)
  • lightly tinted for some thin coverage, nothing too cake-y because I want to look professional at work
Stay posted for my sunscreen reviews on!
To learn more about sunscreen and how to protect yourself from UV radiation and skin cancer:
So as you can see, sunscreen is super important in our daily skin care routines. Big thanks to Joyce for covering me while I am a bit stretched thin at the moment between a busy rotation, studying for my last shelf exam of the year, and prepping for boards. Make sure to check out her blog and follow along on instagram to catch some of the behind the scenes of a busy derm resident!