Butter v.s. Margarine

Bread, cookies, cake, potatoes, pancakes: recipes for all of these and more frequently call for either butter or margarine. But which on should you use? The controversy on which one is better for the consumer's health. has been around for centuries. I would like to say that it all depends on the process by which the butter or margarine is made.

Both butter and margarine are made up of fatty acids. However, few consumers are well educated on what they are, much less the difference between the fatty acids in butter vs the ones in margarine. According to the Bronsted-Lowry theory, an acid is a proton (H+) donor. This means that when reacted with water, the acid will lose a proton (H+). All fatty acids are made up of carbon (C), hydrogen (H), and oxygen (O), arranged in carbon chains with a carbonyl group (-COOH) at one end of the molecule.  They are organic acids represented by figure 1, where R is the part of the molecule that can change.

 

Figure 1: Carbonyl Group

Saturated fats have all of the hydrogens that a carbon can hold, with no carbon-carbon double bonds, thus fully saturating the carbons with hydrogen. Unsaturated fats have double bonds between the carbon atoms. Monounsaturated fats have one double bond, while polyunsaturated fats have several carbon-carbon double bonds. Since atoms on double bonds don't have free rotation, unsaturated fatty acids with double bonds can have one of two isomeric configurations: cis or trans. (fig. 2) Cis isomers have two functional groups adjacent to each other, while trans isomers have the two functional groups opposite each other.

Figure 2

Milk contains butterfat globules (small round particles) made from fatty acids surrounded by membranes made of phospholipids and proteins. Butter is creating by churning (shaking up) the milk or cream which breaks the membranes and allows the butterfat globules to clump together and form butter. Unfortunately, due to the high concentration of milk fat, butter has been found to increase the risk of cardiovascular disease. This is because of the high concentration of saturated fatty acids. (1.) The two most common fatty acids in butter are butanoic acid (fig. 3) and hexanoic acid (fig. 4).

Figure 3: Butanoic Acid

Figure 4: Hexanoic Acid

Margarine is created as a substitute for butter made from unsaturated fatty acids (that is, vegetable oils). However, unsaturated fats have a lower melting temperature, making it less solid at room temperature. Food scientists sought to make it more solid. In 1902, Wilhelm Normann patented the process of hydrogenation of liquid oils to make them more solid. Naturally, vegetable oils are in cis configuration. Hydrogenation is an exothermic reaction and thus releases a lot of heat. This causes the carbon double bond from cis to trans configuration, which the body processes differently. These are the famous trans fats. But are all margarines the same? Most margarines are partially hydrogenated, meaning only some of the double bonds between two carbons are hydrogenated (broken to form hydrogen bonds and single carbon-carbon bonds). Softer, easier to spread margarines are less hydrogenated, leaving more of the double bonds, while harder margarines are more hydrogenated, leaving less double bonds. The variation results in different kinds of saturation and trans fat content in different types of margarine. Trans fats have been found to raise LDL and lower HDL cholesterol.   (2.)

Although the exact biochemical methods by which trans fats produce specific health problems are still being researched, there are several theories that are accepted in the science community. One such theory is that trans fats, due to their configuration, are much easier to stack one on top of another, and much harder to break down. Since trans fats are not common in nature and are usually the results of food processing, the human lipase enzyme that normally breaks down fats can only process unsaturated fats with cis formation and the body does not have any enzymes that can successfully break them down. (3.) Because of this, trans fats can incorporate themselves into the cell membrane the way that they are (without being broken down into a substance that the body can use more easily). This causes an abnormal cell membrane which makes it hard for the membrane to regulate what goes in and out of the cell. In addition to that, trans fats have been found to interfere with the desaturation and elongation of omega 3 fatty acids (which protect the heart).

Many other countries, including Australia and Canada, have legal limits on trans fat content in foods, and Denmark has banned them altogether. (4.) Currently in the United States, the FDA has issued a preliminary determination that partially hydrogenated oils (which contain trans fats) are " not generally recognized as safe". A ban on industrially produced trans fats is to be expected in the near future.  (5.)

However, more and more companies are starting to limit the trans fat content in their food. Some margarine companies have been making margarine without hydrogenating the fatty acids. McDonald’s has stopped cooking it’s french fries in oil containing trans fats and it’s website claims that all of it’s food is free of trans fats. (6.) As people are becoming more educated, they are starting to go back to butter and abstain from margarines and other foods from trans fats.

Overall, opposed to what people have thought in the past, butter is a better alternative to margarine. Although neither are great for your health, trans fats are much more dangerous than saturated fats. The best option for staying healthy is to avoid trans fats.