Gone are the days when our grandmothers slathered their faces with Vaseline and Crisco, hoping the fats would keep their skin firm and dewy. Too bad they didn't know that cold-pressed, plant-based oils are far more effective for moisturizing skin than industrial-strength, petroleum-based products, especially in the winter. "Skin tends to lose moisture in the cold, but heaters inside cars and houses also dry the skin tremendously," says Nadia Arora, ND, of Washington, D.C. And because humidifying oils can be just as beneficial, if not more so, when ingested, it's as important to moisturize from the inside out as the outside in. Here's how.

First line of defense

Nutritious vegetable oils offer benefits beyond beauty. Many, such as olive oil and shea butter—derived from African shea-tree seeds—contain essential fatty acids and vitamin E, which soothe and protect skin. Just as important, plant-based oils also closely mimic skin's structure.

"The whole theory of natural skin care is to use ingredients that your body can recognize: Like likes like," says Barbara Close, author of Pure Skin (Chronicle, 2005).

A better cleanse Cleansing is often synonymous with soap, which strips away both wanted and unwanted oils. Because fats bind to each other, many oils actually can be used to remove makeup and cleanse the face. Beauty author Barbara Close recommends dabbing apricot kernel oil on a cotton pad and gently wiping it over the face. For a more rigorous cleanse, look for products that contain milk and yogurt, which are rich in fats and proteins that bind to unwanted oils. —K.S.

For example, research suggests that lemon oil, when applied topically, may prevent wrinkling and aging by inhibiting enzymes that break down skin cells, while the fatty acids in evening primrose and rose-hip oils plump skin by stimulating collagen production. Because lightweight balms such as jojoba and apricot kernel oil don't clog pores, Close says they are ideal for oily skin. People with superdry skin should try emollient avocado oil and antioxidant-packed almond oil.

Replenish from within

Beauty runs deeper than idioms suggest: Your skin reflects your body's health, and what you eat makes a noticeable difference on the surface. "Dietary fat determines what kind of cellular membranes you have," says Anne Marie Fine, NMD, of Scottsdale, Arizona. "Omega-3s really help your skin look nice because they make the membranes of the cells more flexible, producing supple, elastic skin." Fine recommends eating up to three servings of cold-water fish, such as wild salmon or mackerel, per week or supplementing with 2-3 grams of omega-3-rich fish oil or flaxseed oil per day.

Vitamin E is also crucial for skin health. Because it distributes better between skin layers when ingested, vitamin E is more effective when taken as a supplement rather than applied topically, according to a 2006 study published in the British Journal of Nutrition. "Vitamin E is a potent antioxidant and retards the DNA damage of the cells from sun, pollution, and chemicals," says Arora. A handful of almonds or hazelnuts will satisfy your daily 9-28.5 IU requirement, but also consider incorporating vitamin E-rich foods like soybeans, olive oil, and rice bran into meals.