What is photoaging? Photoaging is characteristic changes induced by chronic sun exposure. Chronic sun exposure, chronological aging and cigarette smoking lead all to skin changes and their effects are additive. The skin becomes scaly, wrinkled, inelastic or leathery. Photodamaged skin appears generally darker. Since both UVB and UVA radiation are capable of causing tissue changes in photoaging; sun protection against both types are necessary. Reducing the total lifetime UV exposure is the goal.
Regular use of a good sunscreen in key to prevention of photoaging.
A sunscreen’s efficacy in blocking UVB radiation is expressed as SPF. Most people apply sunscreen in too thin a film, so the actually “applied SPF” is about half of that on the label. Photoaging is mediated by UVA as well as UVB radiation. For this reason sunscreens with improved UVA protection have been developed. Examples of these UVA coverage ingredients include: Zinc Oxide, Mexoryl, Helioplex and Tinosorb. UVA protection does not exactly parallel the SPF on the current label. The FDA is currently working on new labeling to include an UVA and UVB rating system.
The key to sunscreen use is reapplication. When you apply sunscreen in the morning it had most likely worn off by midday. Keep and extra tube in your desk so you can reapply for the car ride home.
No comments:
Post a Comment