Both butter and margarine are fats. However, there are many different types of fats, and some are healthier than others. Butter and margarine both contain saturated fat and butter also contains cholesterol. Dietary intake of saturated fat and cholesterol must be limited, because these substances can increase blood cholesterol levels and lead to heart disease.
The saturated fat and cholesterol in butter can raise the level of "bad" (LDL) cholesterol in the bloodstream. One tablespoon of butter has more than 7 grams (g) of saturated fat and 33 milligrams (mg) of cholesterol. The daily recommended limit for saturated fat is 20 grams, and for cholesterol is 300 milligrams. However, for people who are at increased risk for or who have heart disease, the daily recommended limit is less than 10 grams of saturated fat and less than 200 milligrams of cholesterol.
Butter is also a good source of the fat-soluble vitamins A, D, E, and K. However, for people who have high cholesterol or heart disease, and those at increased risk for heart disease, a special kind of margarine may be a better choice than butter.
There are many types of margarine available, with important differences among them. Some types should be avoided altogether, and others may be recommended for people with heart disease. Avoid margarine that is made from hydrogenated oils, margarine in stick form, and margarine that contains trans fat (hydrogenated or partially-hydrogenated oils).
The healthiest margarines contain no trans fats and are made with plant sterols and stanols. These margarines are not hydrogenated and are usually sold as liquids or in tubs rather than sticks. Two popular types of these margarines are Benechol and Take Control. Unfortunately, these types of margarine are not suitable for baking or cooking. The healthiest alternatives for baking and cooking are canola or olive oils.