Historically, butter and margarine have been used to fulfill the same purpose within the kitchen. From your morning toast to your batch of cookies, on paper, the differences between the two seem minor. They contain nearly the same exact calories and total grams of fat (about 100 calories per tablespoon and 11-12 grams of fat). However, the real difference lies in the types of fat found in each and their subsequent impacts on health.

Butter

Butter is comprised mainly of 80% milk fat and 20% water. It has long been demonized by the media, due to the fact that it contains large amounts of both saturated fat and cholesterol. However, despite decades of anti-fat propaganda, new studies have shown that these fats are not as harmful as once thought. A large review study published in 2010 looked at 21 studies that included a total of over 340,000 participants. Their final conclusion was that there is absolutely no association between saturated fat and cardiovascular disease. On top of that, butter is also an excellent source of the fat-soluble vitamins A, D, E and K, none of which are found in margarine.

Margarine

Margarine was created to serve as a butter alternative. At its base, the primary ingredient is vegetable oil, which is a liquid at room temperature. In order to take that liquid oil to a more solid form, it is processed and hydrogenated. While margarine tends to contain lower amounts of saturated fat than butter, the process of hydrogenation generates trans fats, a chemically modified alternative meant to model the properties of saturated fat. This gives margarine its harder consistency and also extends shelf life. Trans fats have been linked to reduced levels of good cholesterol (HDL) and increased risks for heart disease.

Unfortunately, not all margarines are created equal. The variations on the market range in consistency from a hard stick to a softer tub. Typically, the harder the margarine is, the more it has been hydrogenated and thus, the higher the trans fat content.

The Bottom Line

When it comes to butter versus margarine, it's not so much a question of which is healthier, but which is less bad for you. In this case, when given the choice between the saturated fat of butter and the trans fat of margarine, the lesser of two evils is butter. However, no matter which you decide to go with, the important thing is to consume these products in moderation. So when you do spread on the butter or margarine, do so sparingly.