WASHINGTON -- If worry about skin cancer doesn't make you slather on sunscreen, maybe vanity will: New research provides some of the strongest evidence to date that near-daily sunscreen use can slow the aging of your skin.
Ultraviolet rays that spur wrinkles and other signs of aging can quietly build up damage pretty much anytime you're in the sun -- a lunchtime stroll, school recess, walking the dog -- and they even penetrate car windows.
Researchers in sunny Australia used a unique study to measure whether sunscreens really help amid that onslaught. Participants had casts made of the top of their hands to measure fine lines and wrinkles that signal sun-caused aging.
The research found that even if you're already middle-aged, it's not too late to start rubbing some sunscreen on -- and not just at the beach or pool. The study of 900 people younger than 55 compared those randomly assigned to use sunscreen daily to those who used it when they deemed it necessary.
Daily sunscreen use was tough -- participants did cheat a little. But after 4 1/2 years, those who used sunscreen regularly had younger-looking hands, with 24 percent less skin aging than those who used sunscreen only some of the time.
Both young adults and the middle-aged experienced skin-saving effects, concluded the study, financed by Australia's government and published Monday in the journal Annals of Internal Medicine.
"These are meaningful cosmetic benefits," lead scientist Dr. Adele Green of the Queensland Institute of Medical Research said in an email interview. More importantly, she added, less sun-caused aging decreases the risk of skin cancer in the long term.
Dermatologists have long urged year-round sunscreen use -- especially for constantly exposed skin on the face, hands and women's neck and upper chest -- but say too few people heed that advice.
Women may have better luck, as increasingly the cosmetics industry has added sunscreen to makeup and moisturizers. Skin experts hope the new study draws attention to the issue.
"Regular use of sunscreen had an unquestionable protective effect," said Dr. Richard Glogau, a clinical professor of dermatology at the University of California, San Francisco.