Can Sunscreen Keep Your Skin From Aging?

Sunscreen season has arrived, along with guidelines for what actually constitutes defense from solar rays and new evidence that a daily slathering may not only protect you from skin cancer and sunburn, it may keep your skin from aging.

That discovery comes from a study published in the journal Annals of Internal Medicine. Australian researchers divided 903 white adults under age 55 — the average age was 39 — into two groups. One group was asked to apply SPF 15 (or greater) sunscreen on their head, neck, hands and arms every morning, after every bath or shower, after spending a few hours in the sun and after sweating heavily. The other participants could use sunscreen however they liked.

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Dermatologists examined images of skin on the back of the subjects' hands at the start of the study and again at the end, four-and-a-half years later. The doctors were not told which patients' exams were from the daily sunscreen group or the control group. The experts saw almost no significant indications of photoaging, the visible aging effect of ultraviolet light on skin which includes lines, wrinkles and coarseness, among the group asked to use the sunscreen daily. Overall, members of that group showed 24 percent less signs of skin aging than the control group. (About three-quarters of the group asked to use sunscreen daily reported that they applied it at least three or four times a week; only about a third of the control group used it as much.)

Dermatologists were not surprised by the results of the Australian research, but quickly declared the findings to be significant given the study's length, number of subjects and location. The participants lived in or around Nambour, a sun-drenched city with weather comparable to South Florida. The most significant previous research of sunscreen's effects on skin involved hairless mice.

If anything, the study may underestimate the benefits of regular sunscreen: The data was collected from 1992 to 1996, before more effective sunscreen formulations came on the market. (The findings are part of a long-term, ongoing skin-cancer prevention study.) Daily application of moisturizer could deliver similar youth-preserving results, of course, but would come without the skin-cancer and sunburn prevention provided by sunscreen.

It remains unclear whether sunscreen would have a similar anti-aging effect on the skin of adults over 55, when the natural effects of aging, including a lifetime of exposure to the sun, tend to accelerate.

Time to Take Sunscreen Seriously

Experts hope the attention being given to the relatively new research may persuade more adults to use sunscreen regularly. "It has been a source of frustration for us that for some sections of the community, the sun-safe message does not seem to be getting through," lead researcher Adele Green of the Queensland Institute of Medical Research told USA Today. "We now know that protecting yourself from skin cancer by using sunscreen has the added bonus of keeping you looking young."

(MORE: Protect Your Skin to Look and Feel Better)

New federal guidelines for sun protection in the United States, geared toward reducing melanoma cases, may have an impact as well. America's skin cancer rate has risen steadily in recent years, according to data from the Centers for Disease Control and Prevention. From 2000 to 2009, the agency reports, skin cancer cases rose about 2 percent annually among both men and women, with the increase taking place mostly in the white population.

It's no newsflash that few of us use sunscreen as directed. The National Institutes of Health advises that we apply about four-and-a-half teaspoons of lotion to our bodies every time we use it. We should apply sunscreen at least 30 minutes before exposure to the sun and reapply it every two hours, or after 80 minutes spent in the water or perspiring.

Not only do most of us fail to follow those guidelines, experts say, we don't even buy the right products. One problem, dermatologists say, is that we pay too much attention to SPF. The Food and Drug Administration advises using sunscreens with a minimum SPF of 15, and products with a lower SPF must now carry a warning that they may not guard against skin cancer. According to the American Academy of Dermatology, a sunscreen with an SPF of 30 blocks at least 97 percent of the sun's rays. Higher SPF products may block slightly more, but still need to be reapplied just as often as any other sunscreen. Any SPF greater than 30, the NIH says, is simply unnecessary, in part because it makes people wrongly think they can reapply sunscreen less often.

Too many sunscreens, especially older products you may find lying around your house, provide protection mostly from ultraviolet B rays, which will ward off sunburn and help limit the risk of skin cancer. But ultraviolet A protection is also crucial to preventing melanoma, meaning you should only buy products that carry the "broad spectrum protection" label. According to new U.S. guidelines, sunscreens with this label must have been proven to defend against both UVA and UVB rays. If the tube of sunscreen at the back of your medicine cabinet doesn't have this label, dump it. And if your current sunscreen is a spray, best to ditch it as well — the Food and Drug Administration has yet to make an official recommendation, but several experts advising the agency are urging it to discourage the use of spray sunscreen, since too much of the product fails to reach the skin and errant sprays can be inhaled.

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The reality, however, is that companies can still sell subpar sunscreen without broad-spectrum protection (or the label), so consumers need to be educated. We should also remember that sunscreen alone may not limit our cosmetic or health risks from sun exposure. Wearing hats, shirts and cover-ups when we're outside, and limiting our time in the sun are other basic steps.

"If you ask most dermatologists," Dr. Alan Boyd of Vanderbilt University Medical Center in Nashville told Reuters Health, "they'll tell you the two things they recommend for people who really want to avoid photoaging: don't smoke and use sunscreen."