Good Fat / Bad FatWebMD Medical Reference from the American Heart Association

Not too many years ago, rule number one for heart-healthy eating was, "Cut down on fat as much as possible." But scientists now know that not all fats are equal and some actually reduce the risk of heart disease. These good-for-you fats include monounsaturated and polyunsaturated fat. On the other hand, some fats are villains when it comes to heart health. Saturated fat and trans fats raise blood cholesterol, which in turn increases the risk of heart attack and stroke.

The good guys

• Monounsaturated fat (found in olive, canola and peanut oils and avocados) and polyunsaturated fat (found in safflower, sesame, soy, corn and sunflower-seed oils and nuts) are good for your heart because they help to lower blood cholesterol levels when you use them to replace other fats in your diet.
• Cold-water fish are also great for your heart. Salmon, albacore tuna, sardines, lake trout, herring and mackerel in particular are rich in a type of polyunsaturated fat called omega-3 fatty acids. Flaxseed and flaxseed oil are also rich in omega 3s. Research has shown that these protective substances slow the development of artery-clogging LDL ("bad") cholesterol, make blood less likely to form the clots that trigger heart attacks and protect against irregular heartbeats that cause sudden death.

And the villains

• Saturated fat is found in foods that are firm at room temperature, such as meat, cheese, butter and luncheon meats as well as other high-fat dairy products and palm, palm kernel and coconut oils. This type of fat is deadly for your heart because it causes artery-clogging LDL cholesterol levels to rise.
• Trans fat (also called trans fatty acids or hydrogenated oil) may be even worse for your heart than saturated fat. Not only does it cause LDL cholesterol to rise but it also triggers a drop in HDL ("good") cholesterol, increasing the risk of developing heart disease and stroke.
• Trans fat comes from a laboratory, not from nature; it's formed when liquid vegetable oils go through a chemical process to make them more solid. Manufacturers use trans fats because they give food a pleasing taste and texture as well as a longer shelf life.
• Trans fat can be found in solid shortenings, stick margarine and commercially prepared cookies, crackers and pastries.
• Many fast-food chains deep-fry french fries and other foods in trans fats.
• The Food and Drug Administration now requires manufacturers to list the amount of trans fat as well as saturated fat and cholesterol on the nutrition label of the packaged foods you buy. But the rule doesn't hold for restaurants or fast-food chains. If you're not sure, ask. A better idea is to go easy on fried foods and french fries and order grilled chicken and a salad instead.
• Replacing just 5 percent of the saturated fat or trans fat in your diet with unsaturated fat can significantly cut your risk of a heart attack.

Putting it all together

It's easier than you think to shift gradually from harmful saturated and trans fats to healthy unsaturated fats. Take it a step at a time.

• Use olive oil instead of butter for cooking. If you don't like the taste, look for extra-light olive oil.
• Switch to mayonnaise made with canola oil.
• When you shop for margarine, choose a product that lists liquid vegetable oil as the first ingredient.
• Eat bread the way that trendy Europeans do dip it in olive oil instead of slathering it with butter.
• Use canola oil instead of butter when you pop up a batch of popcorn at home.
• Help yourself to grilled, baked or broiled fish (particularly cold-water fish) twice a week.

©2006 American Heart Association.