Updated

The key to glowing skin lies in your stomach.

1. Sweet potatoes

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Beta-carotene, which makes these tubers orange, balances your skin's pH, helps combat dryness, and promotes cell turnover, all resulting in smoother skin.

2. Wild salmon

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Sockeye salmon carcasses lie on ice after being cleaned at the Alitak Cannery in Alitak, Alaska July 30, 2008. REUTERS/Lucas Jackson (UNITED STATES) - RTR20PL8 (REUTERS/Lucas Jackson)

The pigment that makes the fish pink, astaxanthin, is a powerful foe of free radicals, rogue molecules that damage cell membranes and DNA and cause skin to age. A study found that eating one serving every five days can prevent actinic keratoses—ugly rough patches that are precancerous.

3. Tomatoes

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The fruit's red pigment, lycopene, is a potent antioxidant that shields skin from sun damage—like sunscreen, but from the inside out. To best absorb lycopene, eat tomatoes with olive oil.

4. Citrus fruits

Citrus fruit

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Vitamin C is essential to building collagen, a vital component of young-looking skin, which starts breaking down in your twenties. Citrus also contains bioflavonoids, which protect skin from UV rays and help prevent cell death.

5. Leafy greens

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(Rosie Acosta)

Spinach, kale, and other greens contain lutein, which protects skin from sun-induced inflammation and wrinkles.

6. Stay away from white foods

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Need another reason to avoid white bread, pasta, rice, and other refined grain products? They're quickly broken down into the ultimate white food: sugar. Once in the bloodstream, sugar bonds with protein and creates advanced glycation end products (aptly abbreviated AGEs), which cause collagen to become inflamed and stiff, leading to wrinkles.

7. Why food is always better than a pill

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"There are so many factors in food that haven't been studied." said Nicholas Perricone, a board-certified dermatologist and author of The Wrinkle Cure, The Perricone Prescription, The Perricone Promise and Forever Young. "It's very likely that these unknowns work synergistically for a bigger benefit than what you can find in a supplement."


8. A bonus drink

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According to dermatologist Leslie Baumann, red wine contains skin-friendly grape-seed extract and resveratrol, two powerful antioxidants. Hops in beer, it turns out, may also offer antioxidant benefits.