Let’s talk about sun protection!
Is it Sunblock or Sunscreen?
Sunscreen: uses a variety of chemical filters that work to absorb the harmful UV rays and convert them into forms that are not as harmful to the skin. They filter or screen the suns UV rays.
Sunblock: reflects, transmits or partially absorbs the suns UV rays from the skin, blocking the rays from penetrating the skins surface. The 2 most common physical blocks are titanium dioxide and zinc oxide.
However, we tend to use these 2 words interchangeably.
What are UVB and UVA rays?
UVB rays: penetrate and damage the outer most layers of the skin and is responsible for causing sunburn and tanning. UVB rays intensity fluctuates depending on the time of day and the time of year. These rays are strongest and pose the highest risk from late-morning to mid-afternoon from spring to fall in our climate.
UVA rays: UVA rays can also cause tanning and sunburn but the wavelength of these rays penetrate much deeper into the skin layers and play a greater role in premature aging and wrinkle formation. UVA rays penetrate deep into the dermis releasing free radicals and causing DNA changes to the cells which have been proven to result in skin cancer. UVA rays are the most common type used in tanning booths and beds. UVA rays account for up to 95% of the UV radiation reaching the earth and these rays maintain the same level of strength during daylight hours throughout the year. This is why it is so important to use your sun protection year round!
How do UVA rays contribute to premature aging?
Collagen and elastin are regulated by a protein digesting enzyme, much like a “Pac-Man”. These enzymes help to chew up and break down old collagen and elastin fibers to make way for the new cells and fibers being synthesized. If these enzymes didn’t break down these old fibers, there would be a buildup of dead cells and old fibers. So these enzymes are always active and play a very important role in keeping our skin healthy, unfortunately UVA rays stimulate this enzymatic activity. This causes the enzymes to “chew up” all of the collagen and elastin in their path, not just the degraded collagen and elastin fibers that need to be removed, resulting in premature wrinkles.
SPF numbers
SPF numbers correlate to the percentage of UVB rays that are either being blocked or screened out.
SPF number tells you how long the sun’s radiation would take to redden your skin when using that product, compared to the amount of time without using sun protection.
SPF 15 blocks about 93% of UVB rays
SPF 30 blocks about 97% of UVB rays
SPF 45 blocks about 98% of UVB rays
SPF 50 blocks about 99% of UVB rays.
Did you notice that SPF numbers only correlate to protecting from UVB rays and not UVA rays? This is why is it important to not just rely on SPF numbers alone, but to also ensure that your sun protection is full or broad spectrum, protecting from both of these harmful rays. Look for products that contain Zinc Oxide, Titanium Dioxide or Avobenzone, these all will protect from the full wavelength of UVA rays.
The FDA requires sunscreens and sunblocks to retain their original strength for 3 years. If your sun protection is past its expiration date, toss it out!
Sun Protection Tips:
It takes 1 ounce (a shot glass full) of sun protection to cover your entire body.
Don’t forget the tops of your feet, your neck, ears and lips.
Apply 15 minutes before going outdoors.
Be sure to reapply at least every 2 hours, or immediately after swimming or sweating.