NEW YORK | Tue Jan 18, 2011 5:32pm EST
NEW YORK (Reuters Health) - Many daily skin creams that claim to provide ultraviolet protection and anti-aging benefits may not have enough of the critical ingredients needed to block UV-A light, according to new research.
That means consumers who rely on these products may be vulnerable to the effects of UV-A rays, including skin darkening, wrinkles, and skin cancer, in some cases.
The finding "is not surprising at all," Dr. Bruce Brod, a dermatologist at the University of Pennsylvania School of Medicine who was not involved in the study, told Reuters Health. "There's a lot of variability in these products."
Many companies sell facial creams claiming UV protection, including L'Oreal, Elizabeth Arden, and Mary Kay. But SPF levels on the bottle only reflect how much UV-B protection the product offers, and companies currently aren't required to back up UV-A claims on their labels, Dr. Steven Wang, the lead author on the study from Memorial Sloan-Kettering Cancer Center in New York City, told Reuters Health.
Even though UV-A and UV-B rays are about equally harmful, Wang said, "UV-A penetrates much deeper into the skin, which can also cause darkening of the skin as well as degrading and destroying the elastins and collagens," proteins in the skin that keep skin firm and protect against wrinkles.
The UV-A rays, Brod said, are "less involved with what we associate with a sunburn-type reaction." But, he said, "they do play a role in (skin) cancer - they damage the DNA of the cells over time."
And Wang pointed out that for many people, UV-A protection may be more important in a skin care product than UV-B protection. "In day-to-day living, most of the UV-B is completely blocked by windows, whereas the UV-A penetrates the windows," he said. "For most of us who work indoors, you really need more UV-A protection than UV-B protection."
Wang and his colleagues analyzed 29 daily facial creams that, according to their labels, protect against UV light. Some of the products claimed to protect against UV-A rays specifically, while others claimed general UV protection. The products had SPF labels from 15 to 50.
When the researchers examined ingredients in the creams for those known to block some kinds of UV-A light, 6 of the 29 products had no active ingredients for UV-A protection at all. Of the 23 products with active ingredients, only 6 of those likely had enough of the right ingredients - including either zinc oxide or a combination of avobenzone and octocrylene - to provide adequate UV-A protection.
While the researchers declined to name the products they tested and how much protection each provided, they did say that more expensive daily creams didn't necessarily offer any more UV-A protection than less expensive creams. The products tested cost anywhere from $1.88 per ounce to $64.71 per ounce, and the most expensive had no ingredients to protect against UV-A light, according to the research team. The findings were published as a research letter in Archives of Dermatology.
The authors did not test the effectiveness of the different products; they only looked at their labeled ingredient contents. While that's a reasonable way to get at their UV-blocking capabilities, "it doesn't tell you the whole story," Dr. Cheryl Rosen, Chief of Dermatology at Toronto Western Hospital and the head of the Canadian Dermatology Association's Sun Awareness Program, told Reuters Health.
The University of Pennsylvania's Brod pointed out that whereas UV-B rays are less damaging during the winter, UV-A levels stay pretty constant throughout the year. Especially considering the lack of regulation of skin care products with UV-A protection, Brod said, people should focus on getting their skin protection through other means - such as avoiding the sun in the middle of the day, and wearing protective clothing and hats.
If you do want to make sure that your daily skin moisturizer is living up to its UV claims, Brod said, "ask your dermatologist for specific recommendations on products that more effectively block UV-A."
And if you choose to use sunscreen or another UV-blocking skin care product, make sure you put plenty of it on, Brod said, or you may be negating any skin protection effects it has altogether.
SOURCE: bit.ly/g4XAnJ Archives of Dermatology, online January 17, 2011.