Sunscreens usually have labels indicating whether they block UVA or UVB rays, or both. What’s the difference for skin aging, skin cancer, and wrinkles -- and why is it significant?
Two types of harmful light rays come from the sun: ultraviolet A radiation (UVA), and ultraviolet B radiation (UVB). According to the American Academy of Dermatologists, both types can cause skin cancer, but each can affect the skin in additional ways:
- UVA radiation can cause photoaging, or premature aging of the skin, resulting in wrinkles, uneven pigmentation, and texture changes.
- UVB radiation is the main cause of sunburn.
So-called “broad-spectrum” sunscreens protect against both UVA and UVB rays. As of June, 2012, the US Food and Drug Administration’s requirements for product labeling have changed so that a sunscreen can only claim to protect against skin aging if it blocks both UVA and UVB rays, and offers an SPF of 15 or higher.
Read more: How does the skin age?
Source:
Sunscreens. American Academy of Dermatologists Public Information Sheet. Accessed August 28, 2012.
http://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreens
