Going Skin Deep

By Ishani GanguliSpecial to The Washington PostTuesday, September 18, 2007; Page HE01
Today's fountain of youth is filled with a strange brew of fairy-tale herbs and chemicals: Chaga mushrooms, osmolytes, coffeeberry extract, polyhydroxy acids, silver tip white tea, rhodiola.
Americans shelled out $44.6 billion for anti-aging products and services in 2004 alone, according to a report by Business Communications. A 2004 online survey of 1, 343 Americans 25 and older, conducted by Harris Interactive, found that 72 percent of women and 13 percent of men had used or were then using an over-the-counter anti-aging product. Nineteen percent of women and 6 percent of men reported using prescription face creams, masks or gels.
Now, Boots No. 7 Restore & Renew Beauty Serum -- the British "anti-aging sensation" that made a hyped transatlantic journey to the States this summer -- has become the latest emblem of our age-old desire not to age.
But what do these supposedly time-defying potions actually do for the tens of millions of Americans of all ages who seek immortal skin on drugstore shelves? The answer is often unclear.
Scientists dispute the definition of aging as well as its mechanisms, so claims that a product can stop or reverse the process are misleading at best, said Thomas Perls, a geriatrician at the Boston University School of Medicine and director of the New England Centenarian Study.
The U.S. Food and Drug Administration does not approve anti-aging creams -- with the exception of a few that count as drugs rather than cosmetics -- and marketers have no requirement to prove that they work. The Federal Trade Commission looks into unsubstantiated claims, but it takes on lawsuits only after dissatisfied customers file complaints.
Anti-aging creams are "not being held to any standard, so we don't know if they work," said Rebecca Kazin, assistant professor of dermatology and medical director of the Johns Hopkins Cosmetic Center at Green Spring Station. She encourages consumers to buy and apply the creams with a healthy dollop of skepticism.
The best bet is to talk to your primary care physician or dermatologist about what skin care is best for your skin type, said Washington dermatologist Sandra Read.
And of course, Perls said, lifestyle choices such as avoiding cigarettes and sun, as well as following a healthful diet, are proven strategies for better skin.
Nonetheless, Americans show no sign of slowing their search for a panacea among the tubes and bottles on drugstore shelves. Here's a closer look at some of the products, their ingredients and the research behind them.
Sunscreens
The approach: Blocking the harmful ultraviolet rays (both UVA and UVB) that cause photoaging, which compounds the skin's natural sagging and deterioration and leads to the most visible signs we associate with aging.The ingredients: Inorganic chemicals (zinc oxide or titanium oxide) and organic compounds (octyl methoxycinnamate or oxybenzone).
What they do: Ingredients such as zinc oxide and titanium oxide reflect harmful rays, while octyl methoxycinnamate and oxybenzone work by absorbing the rays and dissipating them as heat.
Where to find them: Creams that have SPF labels, including Aveeno Positively Radiant Daily Moisturizer with SPF 15, Neutrogena Healthy Skin Anti-Wrinkle Cream with SPF 15.
Do they work?: Sunscreen "is the number one anti-aging product," Kazin said. "I tell people, and they kind of laugh, but it's true. If you use it regularly, you'll definitely look better over time." Read calls it "the cornerstone of all of my treatment for patients."
Retinoids
The approach: Using a multi-step molecular block of photoaging effects.
The ingredients: Retinol, tretinoinWhat they do: These vitamin A derivatives block the degradation of the skin's structural proteins and interrupt the chemical pathways of UV skin damage.
Where to find them: In three prescription creams -- Renova, Retin-A and Avage -- and in over-the-counter retinol creams such as Estee Lauder Diminish Anti-Wrinkle Retinol Treatment.
Do they work?: Retinoids "increase cell turnover, reverse signs of photoaging and allow you to smooth out fine lines and lighten brown spots," Kazin said. Retin-A was developed in the 1970s to treat severe acne. Read said she prescribes retinoids regularly for mild to severe signs of photoaging, though not for women considering pregnancy because retinol can cause severe birth defects. Extensive clinical data and FDA approval support this approach.
Antioxidants
The approach: Replenishing the body's stores of skin-protective antioxidants, which diminish with age.
Examples: Vitamins A, C and E, coenzyme Q10, polyphenols.
What they do: Kazin said antioxidants "slow down the aging process," which occurs when ultraviolet rays from the sun generate free radicals -- reactive forms of oxygen that damage DNA and proteins in skin cells -- trigger inflammation and wreak havoc on the support structures underlying the skin. Antioxidants "basically mop up the free radicals and let the skin heal itself," Read said.Where to find them: SkinCeuticals products (containing vitamins C and E), Boots No. 7 Restore & Renew Beauty Serum (with pro-retinol, a form of vitamin A), Revaleskin products (polyphenols) and the ABRA therapeutic line (polyphenols).
Do they work?:"It is an improvement, a clear improvement," Read said of antioxidants as a whole. Studies show that vitamins C and E are effective in combination, though vitamin C may do little on its own. In studies, polyphenols derived from green tea, fruits and vegetables reduce UV-induced DNA damage and inflammation.
Hydroxy Acids

The approach: Sloughing off dead cells while increasing skin's thickness.
The ingredients: Alpha hydroxy acids (lactic acid, malic acid, citric acid, glycolic acid) and polyhydroxy acids (gluconolacton, lactobionic acid).
What they do: The acids work to increase the skin's thickness and the density of the collagen fibers that are responsible for the skin's strength and elasticity. They also have apparent antioxidant properties.
Where to find them: Neutrogena Healthy Skin Eye Cream (alpha hydroxy acids), Exuviance products (polyhydroxy acids).
Do they work?: Studies show that these fruit acids decrease wrinkling, roughness and discoloration. "They really do produce significant reversal," Read said, though alpha hydroxy acids can cause mild to severe skin irritation.
Fonte: http://www.washingtonpost.com/wp-dyn/content/article/2007/09/14/AR2007091402101_4.html - 18/09/07