The goodness of fat

Omega-3 fats pack a healthy punch. Salmon, tuna and other coldwater fish are excellent sources of omega-3s.
Remember when the word on fat was bad -- all of it? When the term "good fat" would have been considered a dangerous oxymoron? It made no difference whether you sauted your veggies in olive oil or butter. Fat was fat.

Today we're older, wiser and, frankly, more fat-savvy. We now realize that all fats are not created equal. True, some will have your arteries screaming for mercy, but the better fats have been linked to a range of health benefits, from reducing the risk of heart disease to easing arthritis pain.

Today the question is, Is it a good fat or a bad fat? Read on to get the skinny.

Fat facts

The truth is, fat does a body good. Fatty acids (fats) perform a number of vital physiological functions, including:

  • Carrying fat-soluble vitamins (A, D, E and K) and disease-fighting phytochemicals through your bloodstream to nourish your body.
  • Cushioning your heart, kidneys and other organs, protecting them from injury and holding them in place.
  • Producing hormones and other vital chemicals.
  • Providing calories to burn so muscles don't waste away instead (1 fat gram yields 9 calories).
A fat-free diet would not only be boring, it would be dangerous, eventually causing multiple nutrient deficiencies. Along with cutting out the worst fat foods, you'd also end up eating less of the better kinds. Many healthy protein-rich foods, like fish and nuts, and nutritious carbohydrates, like whole grains, contain fat.

The key is to replace the bad fats with the good as much as possible, especially considering all fats are high in calories, with about 100 to 120 calories per tablespoon. Adding good fats without reducing the bad ones won't improve your health, it'll just pack on the pounds.

The bad

Saturated fats
Saturated fat raises the risk of heart disease by increasing LDL-cholesterol, the portion of blood cholesterol called "bad cholesterol." In fact, saturated fat is the main dietary cause of high blood cholesterol. Some studies also have linked breast cancer and decreased insulin sensitivity (the body's inability to respond to or use the hormone insulin effectively) to diets high in saturated fats.

You'll recognize most saturated fats by their firmness. They're usually solid at room temperature. Take, for example, bacon grease that's congealed in the pan after it's cooled. Butter, the trim around meats, vegetable shortening and lard are also types of saturated fats. All dairy fats are saturated, as well, so stick with nonfat or low-fat milks and cheeses.

The saturated fats that don't adhere to the solid-at-room-temperature rule are the tropical oils: coconut, palm and palm kernel. You'll often find them in store-bought baked goods, non-dairy creamers and whipped toppings. Read the nutrition labels to avoid tropical oils.

Trans fats
Like saturated fatty acids, trans fats also raise the risk of heart disease by increasing LDL-cholesterol. These man-made fats are created when oils are processed, or hydrogenated, to make them solid (e.g., stick margarine or candy bars) or to increase the shelf life of crackers, cookies, pies and other packaged foods. When manufacturers hydrogenate corn oil to make corn-oil margarine, they start with a trans-fat-free oil and harden it into a semi-solid fat rife with harmful trans fats. Fried foods also are loaded with trans fats, so it's best to bake, roast and broil.

Because manufacturers usually don't include trans-fat content in the nutrition label, the FDA has mandated that starting January 2006 trans fats be listed on the Nutrition Facts panel under saturated fats.

Butter vs. margarine
Laden with saturated fat and cholesterol, butter was vilified for years and people were encouraged to use margarine instead. Many people swore off butter only to feel duped years later when researchers identified the health hazards of stick margarine. The culprit: trans fats.

Save butter and stick margarine for times when the taste and texture really matter. When nothing but margarine will do, choose a tub that's low in both trans and saturated fats. When butter is a must, spread lightly.

The good

Monounsaturated and polyunsaturated fats
Olive, canola and peanut oils and most nuts are rich in monounsaturated fats. Replace saturated fats with monounsaturated fats -- saut your veggies in olive oil instead of butter, for example -- and you should see LDL levels drop.

Polyunsaturated fats also lower LDL-cholesterol when they take the place of saturated fats. The caveat: they may also lower "good" HDL-cholesterol. As with all food groups, you need a variety, so alternate an oil rich in monounsaturated fats with one abundant in poly's like corn, soybean and safflower oils.

If you need calories to burn during training season, throw a small bag of nuts into your gym bag and cook with extra olive oil, suggests registered dietitian Tara Gidus, spokesperson for the American Dietetic Association. You'll get extra calories and good nutrition at the same time.

The fabulous fats: Omega-3s
Omega-3 fatty acids are a family of polyunsaturated fats that pack a healthy punch. Studies show them to promote brain development and healthy vision in infants, improve cognitive function in the elderly and ease the inflammatory symptoms of arthritis, asthma and Crohn's disease.

Perhaps the most compelling evidence for the benefits of omega-3s is their role in protecting the heart. They reduce the inflammation that precipitates heart disease, make the blood less likely to develop clots, lower the risk of arrhythmias (irregular heartbeats), and in large doses decrease blood triglycerides, says cardiologist Anderson Morris, medical director of Healthsouth Heart College in Birmingham, Ala.

In fact, researchers are taking a closer look at omega-3 fat's effect on arrhythmia specifically in athletes, including how this class of fatty acids may decrease the incidence of sudden death from the heart going out of rhythm. Although arrhythmia deaths in athletes is rare, Morris urges that walnuts and fish or fish oils be part of the nutrition strategy of all athletes.

Omega-3s are essential fatty acids; your body can't make them so you have to get them from food. Walnuts, soybeans and flaxseed are excellent sources of the omega-3 known as ALA. Salmon, tuna and other coldwater fish supply ample EPA and DHA, the longer-chain omega-3 fatty acids. Taking in plant-based and marine-based omega-3 fats is a good idea, says Penny Kris-Etherton Ph.D., distinguished professor of nutrition at Pennsylvania State University, because both types seem to safeguard the heart and are recommended by the American Heart Association.

Marine-based omega-3 fats are important for the brain, too. Much of the brain is made of DHA, and it's known that diet influences the composition of the developing nervous system. Thus, pregnant women, nursing mothers and children especially should seek out marine-based omega-3 fats in addition to plant sources, advises Kris-Etherton.

Unfortunately, omega-3s are sparse in many diets. If you're not a fan of fish, look for some of the new fortified foods. Some breads, margarines and soon-to-be-released Kellogg cereals have added fish oils. Don't worry about fish taste, though. Many will be fortified with DHA from algae rather than fish, and others use microencapsulated fish oils.

How much fat?

Limit fat intake to 20 to 35 percent of your total calories, according to the FDA's Dietary Guidelines for Americans 2005. That's 44 to 78 grams for an active woman on 2,000 calories a day. No more than 10 percent (22 grams) should come from saturated fat, and trans fat intake should be as close to zero as possible.

Fats you can love
Food Fat grams Good source of

Avocado, 1/4 medium 7 Monounsaturated
Tuna, white, canned in water, 3 oz. 2.5 Omega-3
Atlantic salmon, 5 oz. 15 Omega-3
Walnuts, 1 oz. 18.5 Omega-3 & other polyunsaturated
Almonds, 1 oz. 15 Monounsaturated
Peanut butter, 2 Tbsp 16 Monounsaturated
Olive oil, 1 Tbsp 13.5 Monounsaturated
Canola oil, 1 Tbsp 14 Monounsaturated & omega-3
Flaxseed, 2 Tbsp, ground 16 Omega-3 & other polyunsaturated

Jill Weisenberger, M.S., R.D., is a registered dietitian and diabetes educator for Hampton Roads Center for Clinical Research in Norfolk, Va.

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