MONDAY, June 3 (HealthDay News) -- In the never-ending search for the fountain of youth, scientists have looked everywhere under the sun. But a group of Australian researchers now report that the answer lies out of the sun.
Regular daily use of sunscreen appears to significantly slow the process of skin aging among middle-aged men and women, they say.
The finding stems from 4.5 years spent tracking sunscreen use and its ultimate impact on skin quality among more than 900 men and women under the age of 55.
"This has been one of those beauty tips you often hear quoted, but for the first time we can back it with science," said study co-author Adele Green, lab head and senior research fellow with the Queensland Institute of Medical Research at Royal Brisbane Hospital. "Protecting yourself from skin cancer by using sunscreen regularly has the added bonus of keeping you looking younger."
"And the study has shown that up to middle age, it's not too late to make a difference," added Green, who also suggested that sunscreen use is likely to similarly benefit those over 55, though her team did not specifically assess a potential benefit among older users.
The findings appear in the June 4 issue of the Annals of Internal Medicine.
Perhaps surprisingly, the authors point out that, to their knowledge, their current effort is the first rigorous scientific exploration of the potential protective effect of sunscreen on skin aging in people.
Green and her team looked at data collected in a study on skin cancer prevention conducted between 1992 and 1996 in Nambour, Australia.
The authors focused on 903 mostly fair-skinned men and women who were under the age of 55, under the assumption that skin aging in that age category would be brought on primarily by so-called "photoaging," as opposed to simply growing older.
Roughly half the participants worked primarily outdoors, while about four in 10 were regular smokers.
All the participants had been randomly assigned to two sunscreen groups. The first was specifically directed to use SPF 15 sunscreen on a daily basis, applying it to their head, neck, arms and hands every morning, and reapplying after bathing, heavy sweating or spending a few hours outside.
The second group was not told to avoid sunscreen, but rather to use it as they wished.
The study also assessed the potential impact of dietary antioxidants on skin quality. Each group of participants was further divided into half, in which one sub-group was given 30 milligrams of beta-carotene to take on a daily basis, while the other was given a sugar pill (placebo).
Using a process called "microtopography," the team then analyzed skin changes such as shifts in texture and roughness, by looking at the status of each participant's left hand.
The result: Beta-carotene was found to have no appreciable impact on skin aging among those taking the supplement.
But after 4.5 years, regardless of age or gender, those using sunscreen every day were found to have experienced much less skin aging compared with those who did not slather daily.
Over the course of the study period, 24 percent less skin aging was found among the dedicated daily sunscreen group compared to those who used sunscreen only when they wished (presumably less frequently).
That said, Green stressed that the observed skin protection benefit of sunscreen requires some attention to detail.
"This research applies to SPF 15 sunscreen," she said, "and, crucially, applying it correctly on a regular basis. Sunscreen must be applied thoroughly, with a thick coating, and must be reapplied every few hours in case it's washed or sweated off."
"And of course, along with seeking shade and wearing clothing over, sunscreen is a mainstay of sun protection," Green added. "It prevents sunburn in the short-term and skin cancer in the long-term."
And what of non-sunscreen cosmetic products, used by millions of women, that claim to have bundled SPF protection into the mix?
Green cautioned that there is no replacement for true sunscreen.
"Moisturizers with UV protection give brief sun protection," she acknowledged, "but sunscreens last much longer on the skin and provide more durable protection."
Dr. Beth McLellan, an assistant professor at the Ronald O. Perelman Department of Dermatology at the Joan H. Tisch Center for Women's Health at NYU Langone Medical Center in New York City, said the findings add more evidence that sunscreen works.
"We already know that sunscreen can prevent skin cancer and this study shows that regular use of sunscreen can also help prevent aging -- all the more reason to incorporate sunscreen into one's daily skincare regimen," she said.
For more on sunscreens, visit the U.S. National Library of Medicine.
SOURCE: Adele C. Green, Ph.D., lab head and senior research fellow, Queensland Institute of Medical Research, Royal Brisbane Hospital, Queensland, Australia; Beth McLellan, M.D.
assistant professor, Ronald O. Perelman Department of Dermatology, Joan H. Tisch Center for Women's Health, NYU Langone Medical Center, New York City;
June 4, 2013, Annals of Internal Medicine
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