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. They can 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-age, it’s not too late to start rubbing some sunscreen on — and not just at the beach or pool. The study of 900 people under age 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 4½ 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 and middle-age adults 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 important, 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, neck and women’s 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, who has long studied the sun’s effects on skin. He wasn’t involved with the Australian research.

The consumer message: “They can get a two-for-one with sunscreen. They can do something that will keep them healthier and also keep them better-looking,” Glogau said.

In his clinic near Philadelphia, Dr. Eric Bernstein lectures patients who insist they’re not in the sunshine enough for it to be causing their wrinkles, brown spots and dilated blood vessels. Even 15 minutes every day adds up over many years, he tells them — and if they’re using one bottle of sunscreen a year, they’re probably not using enough.

“No one thinks they’re in the sun, and they’re in the sun all the time,” said Bernstein, also a clinical professor at the University of Pennsylvania. “I say, ‘How did you get here — did you tunnel here?’”

The news comes just as tougher Food and Drug Administration rules for U.S. sunscreens are taking effect. For the first time, they ensure that sunscreens labeled “broad-spectrum” protect against both the ultraviolet-B rays that cause sunburn and those deeper-penetrating ultraviolet-A rays that are linked to premature wrinkles and skin cancers.