Monounsaturated fat
In nutrition, monounsaturated fats are fatty acids with one double-bonded carbon in the molecule, with all of the others single-bonded carbons, in contrast to polyunsaturated fatty acids which have more than one double bond.
Fatty acids are long-chained molecules having a methyl group at one end and a carboxylic acid group at the other end. Fatty acid fluidity increases with increasing number of double bonds. Therefore, monounsaturated fatty acids have a solidification temperature that is higher than that of polyunsaturated fatty acids, but still below that of saturated fatty acids.
The most common monounsaturated fatty acids are palmitoleic acid (16:1 n−7) and oleic acid (18:1 n−9). Palmitoleic acid has 16 carbon atoms with the first double bond occurring 7 carbon atoms away from the methyl group. Oleic acid has 18 carbon atoms with the first double bond occurring 9 carbon atoms away from the methyl group. The illustration below shows a molecule of oleic acid.
Monounsaturated fats are found in natural foods like nuts and avocados, and are the main component of olive oil (oleic acid). They can also be found in grapeseed oil, ground nut oil, sesame oil and corn oil. Canola oil is 57%−60% monounsaturated fat and olive oil is about 75% monounsaturated fat.
Olive oil is a key component of the Mediterranean diet, widely regarded as being protective against cardiovascular disease. Although polyunsaturated fats protect against cardiovascular disease by providing more membrane fluidity than monounsaturated fats, polyunsaturated fats are more vulnerable to lipid peroxidation (rancidity) than monounsaturated fats. On the other hand, monounsatuated fatty acids may promote insulin resistance, whereas polyunsaturated fatty acids are protective against insulin resistance. [1]
Natural sources of monounsaturated fat
- Avocados
- Canola oil
- Olive oil
- Peanut oil and other nuts
- Sesame oil
Molecular description: oleic acid
References
- ^ Satoshi Fukuchi (2004). "Role of Fatty Acid Composition in the Development of Metabolic Disorders in Sucrose-Induced Obese Rats". Experimental Biology and Medicine. 229 (6): 486–493. PMID 15169967.