More than 90 percent of the visible skin changes associated with aging are actually caused by the sun's harmful ultraviolet (UV) rays. Dermatologists have long suspected that regular sunscreen use could help slow this skin breakdown, and now Australian researchers have proved it. In a study of more than 900 adults under age 55, a team led by Adele C. Green, MD, PhD, found that subjects who applied an SPF 15+ broad-spectrum (UVA/UVB) sunscreen every morning (and reapplied it after sweating, bathing, or spending more than a few hours outdoors) reduced their skin aging by 24 percent.
The study lasted more than four years, during which time investigators examined subjects’ skin every three months for signs of aging. Ultimately, members of the daily sunscreen group (who were instructed in how to use it properly every day) showed significantly less skin aging than members of the control group (who were asked only to carry on with their customary sunscreen use).