Dermatologist Nicholas Perricone, the author of Forever Young, a book about how eating right can keep you looking younger than your years says, "The wrong choice of foods cause inflammation down to the cellular level and while you can't see it, that inflammation leads directly to wrinkling, sagging, and premature aging."

Kicking nicotine and avoiding excessive sunlight will help, but the secret to healthy-looking skin is the food you eat. Here is a list of foods that you can eat to prevent that from happening.

Sweet potatoes

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

Wild salmon

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.

Tomatoes

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.

Citrus fruits

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

Leafy greens

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

Stay away from white foods

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.

Food is always better than a pill

There are so many factors in food that haven't been studied. It's very likely that these unknowns work synergistically for a bigger benefit than what you can find in a supplement.

Wine

Red wine contains skin-friendly grape-seed extract and resveratrol, two powerful antioxidants. Hops in beer may also offer antioxidant benefits.