Margarine or Butter?

Margarine usually tops butter when it comes to heart health.

Margarine is made from vegetable oils, so it contains no cholesterol. Margarine is also higher in "good" fats — polyunsaturated and monounsaturated — than butter is. These types of fat help reduce low-density lipoprotein (LDL), or "bad," cholesterol, when substituted for saturated fat. Butter, on the other hand, is made from animal fat, so it contains cholesterol and high levels of saturated fat.

But not all margarines are created equal — and some may even be worse than butter. Most margarines are processed using a method called hydrogenation, which results in unhealthy trans fats. In general, the more solid the margarine, the more trans fats it contains — so stick margarines usually have more trans fats than do tub margarines. Like saturated fats, trans fats increase blood cholesterol and the risk of heart disease. In addition, trans fats can lower high-density lipoprotein (HDL), or "good," cholesterol levels.

When selecting a margarine, choose one with the lowest trans fat content possible and less than 2 grams total of saturated plus trans fats. Manufacturers are required to list saturated and trans fats separately on food labels. Also, margarines fortified with plant sterols can help reduce LDL cholesterol levels by more than 10 percent. The amount of daily plant sterols needed for results is at least 2 grams. The American Heart Association recommends foods fortified with plant sterols for people with levels of LDL cholesterol over 160 milligrams per deciliter (4.1 mmol/L).

However, if you don't like the taste of margarine and don't want to give up butter completely, consider using whipped butter or light or reduced-calorie butter. There are also spreadable butters with vegetable oils added. Per serving, these products have less fat and calories than regular butter. The important thing is to use these products in small amounts — just enough to add flavor to the foods you're eating.

Mayo Clinic cardiologist Martha Grogan, M.D.