Difference Between Saturated and Unsaturated Fats

Main Difference – Saturated vs Unsaturated Fats

There are two types of fats known as saturated and unsaturated fats. Many people believe that all fats are bad and are what make you obese. This is not a true; you need a specific amount of fat in your daily diet to keep your body healthy. Therefore, it is important to understand which type of fat is healthier than the other. In other words, it is important to understand the difference between saturated and unsaturated fats to select the healthy option. Saturated fat is a fat compound in which the fatty acids all have single bonds. In contrast, an unsaturated fat is a fat compound in which the fatty acids have both single and double bonds. This is the main difference between saturated and unsaturated fats. In addition, saturated fats can increase your risk of coronary heart diseases and other metabolic syndromes while unsaturated fats can help keep your body functioning healthily. This article explores the different chemical and physical properties of saturated and unsaturated fats.

What is Saturated Fat

Saturated fat is a  fat molecule that comprises of two kinds of smaller molecules known as monoglyceride and fatty acids. These fatty acids in the saturated fat molecule have only single bonds. Fatty acids are made of long chains of carbon (C) atoms, and some of these carbon atoms are connected by single bonds (-C-C-) only. Fatty acids containing double bonds can react with hydrogen to form saturated fats. Most animal fats are considered as saturated fat. When saturated food is exposed to the atmosphere, they are not susceptible to further oxidation and rancidity.

What is Unsaturated Fat

Unsaturated fat is a fat or fatty acid that has both single bonds and double bonds. In other words, these fat molecules should have at least one double bond within the fatty acid chain. Unsaturated fats can be again subdivided into two categories. They are monounsaturated and polyunsaturated fats. Monounsaturated fat contains only one double bond whereas polyunsaturated fat contains more than one double bond. When unsaturated food is exposed to the atmosphere, they are susceptible to further oxidation and rancidity.

Difference Between Saturated and Unsaturated Fats

Definition

Saturated fat: A saturated fat is a fat, or fatty acid that has only single bonds.
Difference Between Saturated and Unsaturated Fats

Figure 1: Example of saturated fatty acid – Myristic acid

Unsaturated fat: An unsaturated fat is a fat, or fatty acid has both single bonds and double bonds.Main Difference - Saturated vs Unsaturated Fats

Figure 2: Example for unsaturated fatty acid – Oleic acid

Categorization

Saturated fat: Saturated fat is not further dived into subcategories.

Unsaturated fat:Unsaturated fat is subdivided into two categories. They are monounsaturated and polyunsaturated fats.

Physical Nature

Saturated fat: Due to their chemical structure, saturated fats have a solid consistency at room temperature.

Unsaturated fat: Due to their chemical structure, unsaturated fats have a liquid consistency at room temperature.

Most Common Examples

Saturated fat: Palmitic acid, stearic acids, lauric acid and myristic acid are common examples of saturated fat.

Unsaturated fat: Palmitoleic acid, oleic acid, myristoleic acid, linoleic acid, and arachidonic acid are common examples of unsaturated fat.

Most Common Sources

Saturated fat Most animal derived fats are considered as saturated fat. Examples;

  • “Tropical” oils such as palm kernel, coconut and dairy products rich in Lauric and myristic acids
  • meat, eggs, cacao, and nuts are primarily rich in palmitic and stearic acids
  • Saturated fats are also rich in processed and deep fried foods such as sausages, pizza, burgers, pastries,

Unsaturated fat: Most plant-derived fats are considered as saturated fat. Examples are oils from avocado, nuts, vegetable oils (such as canola and olive oils), soybean, rapeseed, evening primrose flower, cereal, fish oils and sunflower oils.

Dietary Recommendation

Saturated fat: According to the American Heart Association recommendation, less than 7% of your daily caloric intake should consist of saturated fat. But for a normal and healthy person, daily recommendation is 10% of your daily caloric intake should consist of saturated fat.

Unsaturated fat: There are no specific recommendations for unsaturated fats.

Analysis Methods

Saturated fat: Saturated fatty acids are separated by gas chromatography of methyl esters or thin-layer chromatography and gas chromatography, and mass spectroscopy can be used to analysis these molecules.

Unsaturated fat: Unsaturated fatty acids are separated by gas chromatography of methyl esters or thin-layer chromatography and gas chromatography, and mass spectroscopy can be used to analysis these molecules. In addition to that, iodine value can be used to determine the proportion of unsaturated fat.

Susceptibility to Oxidation

Saturated fat: When saturated food is exposed to the atmosphere, they are not susceptible to further oxidation and rancidity.

Unsaturated fat: When unsaturated food is exposed to the atmosphere, they are susceptible to further oxidation and rancidity.

Health Aspects

Saturated fats: High amount of saturated fats consumption;

  • May increase LDL-cholesterol and risk of heart disease
  • Increase risk of type II diabetes and obesity

Unsaturated fat: Unsaturated fats are associated with various health benefits. They are;

  • Reduce the risk of cancer development
  • Prevent cardiovascular disease, platelet aggregation and hypertension
  • Help to reduce LDL cholesterol (Bad cholesterol) and increase HDL cholesterol (good cholesterol)
  • Have the anti-inflammatory activity and lowers markers of inflammation in the blood such as C-reactive protein and interleukin 6. However, some unsaturated fats have both pro-inflammatory and anti-inflammatory properties.
  • Reduce the risk of rheumatoid arthritis
  • Supplements are given to autism children and Alzheimer’s diseases patients
  • Brian development in small childrenDifference Between Saturated and Unsaturated Fats -infographic

In conclusion, both saturated and unsaturated fats have several roles in the human body. In addition to being the principal component of stored fat, they also serve as important building blocks of cell membranes and regulate inflammatory processes. In nutritional standpoint, unsaturated fats are better than saturated fat. But they are equally energy-dense  molecules so you should consume both in self-control level as these can incorporate calories to the daily diet.

References:

Okuyama, H., Ichikawa, Y., Sun, Y., Hamazaki, T. and Lands, W.E.M. (2006). ω3 Fatty Acids Effectively Prevent Coronary Heart Disease and Other Late-Onset Diseases – The Excessive Linoleic Acid Syndrome. In Okuyama, H. Prevention of Coronary Heart Disease. World Review of Nutrition and Dietetics. pp. 83–103.

Ricciotti, Emanuela and FitzGerald, Garret, A. (2011). Prostaglandins and inflammation. American Heart Association Journal, 31(5): 986–1000.

Scorletti, E. and Byrne, C. D. (2013). Omega-3 fatty acids, hepatic lipid metabolism, and nonalcoholic fatty liver disease. Annual review of nutrition, 33(1): 231–48.

Vafeiadou K, Weech M, Altowaijri H, et al. Replacement of saturated with unsaturated fats had no impact on vascular function but beneficial effects on lipid biomarkers, E-selectin, and blood pressure: results from the randomized controlled Dietary Intervention and VAScular function (DIVAS) study. Am J Clin Nutr. 2015 Jul;102(1):40-8.

De Souza RJ, Mente A, Maroleanu A, et al. Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ 2015; 351:1-16.

Image Courtesy:

“Two-dimensional representation of the saturated fatty acid myristic acid” by Calvero. – Selfmade with ChemDraw., (Public Domain) via Commons Wikimedia 

“Oleic acid structure” by D.328 2008/11/22 03:04 (UTC) – selfmade by ChemBioDrawm, Illustrator, Inkscape, (Public Domain) via Commons Wikimedia 

About the Author: Geesha

Geeshani has a BSc (Hons) degree in Food Science and Technology and Master's degree in Food and Nutrition. She is currently a PhD Student at the Massey Institute of Food Science and Technology. Sharing what she learned is a passion of hers and enjoys writing.