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You haven't had a sunburn since high school, are an expert at layering antioxidants, and ditched the cigarettes. But when it comes to antiaging, the following skincare misconceptions might be stealthily leading you to wrinkling, sagging, and spots.

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MYTH: Standing in the shade protects you from UV damage.

FACT: Just because you can't feel the sun on your skin doesn't mean ultraviolet radiation isn't there. As you, say, walk to work on the shady side of the street, sneaky diffuse irradiation (scattered solar beams) present in the atmosphere during daylight hours accounts for a whopping 80 percent of your annual dose of UV exposure. "Sun damage is cumulative," explains New York dermatologist Dr. Debra Jaliman, so you simply must wear SPF 30 broad-spectrum sunscreen all year round. "Even when it's cloudy, the sun penetrates through," she says.

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MYTH: Everyone's skin ages the same way.

FACT: Here's where those with oily complexions get the last laugh. You may have cursed your T-zone in college, but oil naturally moisturizes and protects skin from aging. Dry skin shows fine lines earlier, no thanks to an impaired outer barrier that lets youth-preserving moisture out and aging irritants in. For dry types, Jaliman recommends a lightweight moisturizer with hyaluronic acid, a molecule that attracts water. (We like Neocutis Hyalis 1% Hyaluronate Refining Serum, $95.)

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MYTH: Daily exfoliation keeps skin young.

FACT: This isn't entirely false, but for some skin types, daily peels or scrubs can do some serious damage. "If you have sensitive skin, eczema, or rosacea, you can over-exfoliate and irritate your skin," says Jaliman. In lieu of aggressive, abrasive sponges, she prefers gentle exfoliation for all skin types with a cleansing brush system like Clarisonic's (from $119) to slough off dull, old-looking skin. If your skin can tolerate it, add glycolic pads (such as Bliss That's Incredi-'peel'!, $49) once a week to rev up radiance.

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MYTH: Your diet has little to do with how your skin ages.

FACT: "There's interesting new research linking diet and skin health," says Los Angeles dermatologist Dr. Jessica Wu. She points to high-glycemic foods (white foods such as rice, pasta, bread, and sugary sweets) as super skin-enemies because they trigger the body to produce insulin, which causes age-accelerating inflammation. Instead, load up on colorful vegetables that fight swelling and redness, suggests Wu. "One study showed that those who eat more green and yellow vegetables have fewer wrinkles, especially crow's-feet, around the eyes."

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Alexandra Verinciuic
MYTH: Wrinkles are formed by facial expressions.

FACT: True, but the same skin folding that causes wrinkles when you move your face (marionette lines, the "11s" between brows, etc.) can happen while you're sleeping on your side or stomach. Skin produces less elastic tissue over time, which means it can't bounce back as easily (or at all) after years of being smushed into a pillow, explains Wu. "I tell my patients to try to train themselves to sleep on their backs," she says. Try the Sobakawa Cloud Pillow, $20, or similar models designed to keep your head in place.

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inexpensive skin care products that work
Jeffrey Westbrook
MYTH: Good skincare can erase signs of aging.

FACT: It helps, but skin also depends on good circulation. If your arteries are in bad shape, expect a dull complexion. Get early treatment to normalize blood pressure and help prevent this damage.

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