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.