What You Need To Know About Sun Protection

What You Need To Know About Sun Protection

Dear Kosterina Family,

The Summer season is officially in full swing and as we spend more weekends hitting the trails, the water, the court, or the beach, we always want to remember to apply our SPF. 

Sunscreen is one of the most-studied anti-carcinogenic and anti-aging drugs. Plus, it's so easy to add to our everyday routines, but why is it so important and how does it work? Today we are sharing a roundup of some of the most interesting findings and learnings on sunscreen so we can enjoy the outdoors in a safe and enjoyable way. Plus, we all want to keep our "youthful glow" for as long as possible right?

What are UV Rays?

UV rays = Ultraviolet Radiation, a very powerful form of solar energy.  UV rays divided into UVA, UVB, and UVC rays (UVC is fully-blocked by our the Earth's ozone and doesn't reach the ground). UV rays are among the most-studied carcinogens and are linked to several cancers.

UV rays can damage your skin barrier in two major ways:

  1. Increased expression of matrix metalloproteinases in human skin, resulting in the degradation of the extracellular matrix (collagen, fibronectin, elastin, and proteoglycans) contributing to accelerated aging (photoaging). 
  2. UV rays are free radicals, contributing to oxidative stress, damaging our DNA and skin barrier, further contributing to accelerated aging and cancer (photocarcinogenesis).

 UVA Rays vs UVB Rays

  • UVA rays "A"ge your skin.  These rays have a much longer wavelength that penetrate deeper into your skin, damaging your collagen. This results in an increase of fine lines, wrinkles, and hyperpigmentation.
  • UVB rays "B"urn your skin.  These rays have a shorter wavelength that contribute to the blistering, peeling, and redness that many of us are all too familiar with.

To protect yourself from both, try finding a sunscreen that says "Broad Spectrum".  Likewise, international brands have a "PA" rating that tells you how much UVA protection you are getting.


This is the most important step in our skincare routine.  Sunscreen is regulated by the FDA as a drug, meaning that it is constantly being screened for improvements and innovations.  There are two main sunscreen types that you can choose from: chemical or mineral.

Chemical sunscreens use organic chemical filters to absorb UV radiation before it has time to reach your dermis.

  • Common organic ingredients include oxybenzone, homosalate, avobenzone, and octinoxate. 
  • These filters tend to absorb quicker into your skin, but require a short rest time time on your skin before becoming fully-active.  We recommend waiting 10-20 min after applying to go out into the sun. 
  • These sunscreens can be more irritating to sensitive skin. 
  • Some research suggests that these organic filters could be contributing to hormone imbalances, however, these studies are too limited to be fully conclusive.  Risk is still determined to be low. The FDA is continuing to monitor and regulate these chemical ingredients.   
  • Chemical filters can have adverse effects on our coral reefs

Mineral sunscreens use inorganic filters to reflect UV rays off of your skin. 

  • Common ingredients include zinc oxide and titanium dioxide. 
  • These filters sit on top of your skin and tend to cause more of a white cast (that pasty white look that we all grew up with). 
  • Tends to be less irritating to sensitive skin and better for the environment, just be sure to find mineral sunscreens that don't have a silicone coating.

Sunscreen is an anti-carcinogenic drug that we can all use!  Dermatologists recommend that you reapply at least every two hours, even more if you've been sweating or enjoying time in the water.  Even those who are blessed with more melanin are encouraged to wear sunscreen.  Particularly, POC are more likely to face terminal illness related to skin cancer.  This can be due to lack of accessible resources, the myth that more melanin means less sunscreen, and cancer being seen at later stages in POC.

What is SPF?

  • SPF stands for "Sun Protection Factor".  This rating tells you how much protection you are receiving from UVB rays.
  • The difference between SPF ratings is not always intuitive.  According to the EWG, SPF 15 blocks 93% of UVB rays; an SPF 30 blocks 97%; an SPF 50 blocks 98%, and an SPF 100 blocks 99%.

How can you fortify your sun protection?

  • Incorporating antioxidants into your topical skincare routine and diet is a great way to fight UV damage.  This study suggests that a regular intake of polyphenols could be a key component in fighting UV oxidative stress.
  • Likewise, a high-antioxidant topical skincare can soothe, heal, and calm irritated and damaged skin.
  • Wear protective clothing.  UV protective clothing can have a "UPF" rating, which is SPF's fashion parallel.  We like pairing our sunscreen with a hat, UV-protective sunglasses, and a nice umbrella.
  • Don't leave your sunscreen in the heat for too long and don't use it if it has expired. The cosmetic compounds in these formulas will degrade overtime, resulting in less and less efficacy.

However, regardless of how much sun protection you put on, fine lines and wrinkles eventually get the best of us all. While we may want to hang on to our youth for as long as we can, aging is a privilege that many do not get to enjoy, so we learn to embrace and love our "wisdom lines".  Something as simple as applying sunscreen can help us live to see even more.

Peace, Love & EVOO,