Choosing A Sunscreen
With summer on the way, it will soon be time to break out the sunscreen again. But which sunscreen is best? With the proliferation of sunscreen products on the shelves, how do you know which kind to buy?
In the course of our exposure to the sun, our skin absorbs both UVB and UVA ultraviolet rays. UVB rays cause sunburn, darkening of the skin, and damage to the outer layer of the skin that can cause cancer. UVA rays penetrate deeper into the skin, causing skin aging, lines and wrinkles, and cell damage that can lead to cancer. It is important to choose a sunscreen that offers protection against both UVB and UVA rays, which is often referred to as “broad-spectrum” sunscreen.
UVB vs. UVA Protection
On every bottle of sunscreen you see on supermarket shelves, you will see a large number declaring the SPF, or Sun Protection Factor, of the sunscreen. Common SPF numbers range from 15, 30, 45, and even higher.
However, what you may not know about SPF is that it only measures a sunscreen’s effectiveness against UVB rays, and not the harmful UVA rays that penetrate deeper into the skin. Unfortunately, in the U.S. there is no current method of determining how much your sunscreen will protect against UVA rays.
One way to check if your sunscreen protects against UVA rays is to see if it contains Parsol 1789 (or avobenzone) or Mexoryl, two chemicals that filter UVA rays. However, the safety of these chemicals has recently been called into question, as they may mimic human hormones. The long-term effects of Parsol 1789 and Mexoryl are not clear.
A better defense against UVA rays is sunscreen that physically blocks the rays from reaching your skin. Sunscreens with zinc oxide and titanium oxide may do a better job of protecting your skin, and as they are not absorbed by the skin, seem to be safer. The downside of physical blocking agents is that they can form a white film on top of the skin that many people do not like. Nevertheless, they may be your best option.
Some sunscreens sold in other countries have some methods for determining how much they block UVA rays. In Japan, the designation PA+, PA++ and PA+++ indicates progressively better UVA protection, while in the UK, up to five stars placed next to the SPF number indicate how well the sunscreen protects against UVA rays.
Is Higher SPF Better?
Counter to what you might expect, an SPF of 30 does not mean it is twice as effective as an SPF of 15. SPF 15 blocks 94% of the sun’s UVB rays, whereas SPF 30 blocks 97%. In suncreens higher than SPF 45, any improvement is minimal. However, doctors recommend an SPF 30 over SPF 15, because most people do not apply enough sunscreen to make the SPF as effective as promised.
Apply Plenty of Sunscreen and do it Early
Don’t be afraid to slather it on! Most people don’t apply enough sunscreen to make the sunscreen fully effective. Adults should apply about 2 tablespoons of cream sunscreen, and children about half that.
Apply sunscreen 30 minutes before you plan to go out in the sun so it has time to absorb into your skin.
Reapply frequently — even if you are not swimming or sweating, sunscreen can disappear from your skin after a few hours. If you are swimming, use a waterproof sunscreen, and reapply sunscreen after you exit the water.
This post was included in the All Things Family Blog Carnival:The Great Outdoors Edition.