Introduction

The types of fats that we ingest can either enhance our health or harm it. In general, unsaturated fats are considered the “healthier fat”. Diets high in saturated and trans-fat increase the risk of cardiovascular disease and may be linked to certain forms of cancer and neurological diseases. No more than 6% of your total intake of fat should be saturated fat. You should avoid trans fats altogether. Let us examine why?

Learning

The long fatty acid tails of lipids can be saturated or unsaturated. Saturated means that carbons in the tail cannot hold any more hydrogens. The carbons are packed tightly together which means the fat is solid at room temperature. Some examples are animal fats found in meats and the fat found in butter. Unsaturated fats are oils, which are liquid at room temperature. The carbon chains in the tails contain double bonds which means there are less hydrogens bonded to the carbons. Examples of these fats are the oils found in plant seeds.

The location of the double bonds in the unsaturated fatty acid chain can result in a kink if two of them are located together on the same side of the chain. This is called a cis configuration. This means the tails cannot pack closely together, keeping the fats liquid at room temperature. If the double bonds are located on opposite sides of the tail, this is called the trans configuration. This results in a straighter chain.

Unsaturated fats help lower cholesterol levels in the blood while saturated fats add to the plaque that can form on the inside of blood vessels.

What is bad about a hydrogenated oil? The food industry bubbles hydrogen in an oil to unsaturate the fatty acid chains. These are called trans fats. This results in an oil that is solid and easier to package. An example of this is margarine. Studies have found that these types of fats raise the levels of LDL’s or low-density lipoproteins. The higher levels result in more plaque deposits in arteries.

Good Fats vs Bad Fats

Nutritional Example:

Examining the nutritional label, we can see that this brand of Macaroni and Cheese contains a total of 12 grams of fat per serving.  3 out of the 12 grams of fat are ‘Saturated’ while 3 grams are considered ‘Trans’.  Trans fats are ‘artificially straightened’ fat molecules created through a process of hydrogenation.  Since trans fats cannot be metabolized as efficiently as other fat molecules and have been linked to elevated cholesterol levels

Summary

• Fats can be saturated, which means their fatty acid chains contain carbons that have the maximum number of hydrogens bounded to them. The fats can be tightly packed together and results in a fat that is solid at room temperature.
• Unsaturated fats have fatty acid tails that have carbons with double bonds, which results in less hydrogens and fatty acid tails that are bent or have a kink in them. These are fats that are liquid at room temperature.
• Trans fats are fats that have been hydrogenated (hydrogen bubbled into them) to make the fatty acid tails straighter with the double bonds. This solidifies oils for the food industry and results in higher LDL levels, or the bad cholesterol.

Source:

“Lipids.” By OpenStax Biology 2e. Retrieved from: https://openstax.org/books/biology-2e/pages/3-3-lipids/ Licensed under: CC-By: Attribution