Fats are crucial to health. In fact, the American Heart Association recommends 20 percent to 30 percent of your dietary calories come from fat. The trick is to know and eat the right kinds—namely, those with high percentages of healthy mono- and polyunsaturated fats, including several common and less-familiar oils.

“Almost every oil has saturated and unsaturated components,” says John La Puma, MD, internal medicine and nutrition specialist and coauthor of The RealAge Diet (HarperCollins, 2001). “Within the unsaturated there are two kinds, mono and poly, and within the poly there are omega-3 and omega-6 fats.” These omegas are known as essential fatty acids (EFAs), fats the body needs but can’t produce on its own.

Polyunsaturated fats’ health benefits are well-documented, including significant cholesterol-lowering effects and positive correlation to reducing heart-disease risk (Annals of Pharmacotherapy, 2002, vol. 36, no. 12). Monounsaturated fats also show these benefits (Lancet, 2002, vol. 360, no. 9344; New England Journal of Medicine, 2003, vol. 348, no. 26).

Oils can be incredibly flavorful, so a little can go a long way. For cooking, you’ll need to know their smoke point—the temperature at which an oil starts to break down and emit smoke. Many polyunsaturated-rich types, including nut and seed oils, are relatively fragile and lose nutritional value when exposed to light and heat, while others tolerate heat and still retain their healthy benefits. Knowing which oil to use for a particular application will ensure you get the most from your fats.

Olive oils
Olive oil’s nutritional profile, flavor, and versatility make it the ultimate kitchen workhorse; it has the highest monounsaturated-fat percentage—about 76 percent—of all common oils. Studies abound supporting olive oil’s role in reducing heart-disease risk, even with short-term use (Nutrition, Metabolism, and Cardiovascular Diseases, 2001, vol. 11, no. 4 Suppl). Chef Russell Scott, an instructor at the Culinary Institute of America in Hyde Park, New York, loves its versatility. “There are lots of varieties, and it has a great flavor that holds up during cooking,” he says. Olive oil’s relatively high smoke point makes it suitable for sautéing and baking, but not frying.

Many extra-virgin olive oils have a strong flavor that works well with vinegars, dressings, and marinades. Some cooks prefer light olive oil for a more neutral flavor, but remember, “light” doesn’t mean low calorie; it still has the same amount of fat.

Nut oils
“Most nut oils are polyunsaturated, which means they contain EFAs—primarily omega-6s, though some contain a fair amount of omega-3s,” says La Puma. Walnut oil, rich in omega-3s, helps inhibit LDL (bad) cholesterol oxidation (Journal of Nutrition, 2001, vol. 131, no. 11), and almond oil is gaining kudos for helping to lower LDL cholesterol and triglyceride levels while increasing HDL (good) cholesterol (Journal of Nutrition, 2002, vol. 132, no. 4). The bonus: Nut oils are packed with flavor. “In this country, we’re very generic in our cooking, and most people don’t know about nut oils,” says Scott. With a stronger flavor than most oils, he says, just a drizzle can wake up an otherwise bland dish.

Most nut oils are delicate, with low smoke points, so Scott suggests adding them at the end of cooking. “Say you’re sautéing chicken breasts. Just before you serve, drain off your neutral-flavor, high-smoke-point cooking oil, then drizzle the chicken with walnut oil, toss it in the pan and serve,” he says.

Seed oils
Like nut oils, seed oils tend to be rich in unsaturated fats. Sesame seed oil, a favorite in Asian cuisine, contains an equal balance of mono- and polyunsaturated fats, but can withstand higher temperatures than many seed and nut oils. Research indicates that sesame oil contains intrinsic cancer-preventing and heart-healthy agents (Pharmacological Research, 2002, vol. 45, no. 6; Nutrition and Cancer, 2001, vol. 39, no. 1). Toss it with pasta and in salads for a unique flavor.

Pumpkin seed oil, a recent introduction to American stores, boasts abundant polyunsaturated fats and antioxidants (Pharmacological Research, 1997, vol. 35, no. 5). “It’s really dark green and incredibly flavorful; it tastes like toasted pumpkin seed essence,” La Puma says. He recommends it on whole-grain salads or in winter squash dishes in place of butter.

High-heat oils
When the cooking temperature will be higher (frying, for example), try grapeseed oil or rice bran oil. Both have high smoke points, so less oil is absorbed during cooking—a calorie-saving plus. Grapeseed oil is particularly high in polyunsaturated fats and heart-healthy vitamin E and low in saturated fat. “Its light texture is nice for fruit salads and delicate salads like baby greens where olive oil might be overpowering,” Scott says. “It’s light and refreshing, with a little sweetness to it as well.”

Rice bran oil is fairly new but shows great nutritional promise, including LDL cholesterol-lowering properties (Journal of the American College of Nutrition, 2000, vol. 19, no. 5). This is surprising considering it has a relatively high percentage of saturated fats. Researchers speculate that some other element in rice bran yields this heart-healthy benefit.

With any oil, check the label and choose those with predominantly mono- and polyunsaturated fats. Experiment to learn which oil offers the greatest nutritional benefits, best taste, and cooking properties you want. Then relax and enjoy these new flavors: If selected wisely, you can have fun chewing the fat.

Mitchell Clute is a writer, musician, and passionate cook living in Crestone, Colorado.