What is CLA?
Conjugated Linoleic Acids (CLA) - composed of 18 carbon-chain fatty acids with two double bonds occurring on adjacent carbon atoms - is produced during the natural biohydrogenation of linoleic acid (18:2) by rumen bacteria.1,2
Dairy products are the richest source of CLA, providing about 70% of total dietary CLA, compared with about 25% from beef and smaller amounts from other ruminants (i.e., sheep, goats).2
There are many different CLA isomers, but the biological functions of only two - cis-9,trans-11 (c-9,t-11 CLA) and trans-10,cis-12 (t-10,c-12 CLA) - have been studied extensively.1,2 The dominant one in ruminant fat, accounting for up to 90% of total CLA, is c-9,t-11 CLA (also known as rumenic acid); t-10,c-12 CLA is a very minor component. Moreover, as much as 40% of the trans in Canadian dairy fat is vaccenic acid, an isomer of oleic acid, of which at least 20% is converted to CLA in the human body.3-4 In contrast, elaidic acid, the dominant trans in industrial fats, is not.2
Structural differences between cis and trans double bonds in an unsaturated fatty acid
Structural differences between non-conjugated and conjugated double bonds in a polyunsaturated fatty acid
For more information, visit The CLA Network
References
- Parodi PW. 2004. Milk fat in human nutrition. Aust J Dairy Technol 59:3-59.
- Lock AL et al. 2005. The biology of trans fatty acids: Implications for human health and the dairy industry. Aust J Dairy Technol 60:3-12.
- Turpeinen AM et al. 2002. Bioconversion of vaccenic acid to conjugated linoleic acid in humans. Am J Clin Nutr 76:504-510.
- Mendis S et al. 2008. Fatty acid profile of canadian diary products with special attention to the trans-Octadecenoic acid and conjugated linoleic acid isomers. J AOAC Int Vol 91 (4).
Keywords: conjugated linoleic acid
Nutrients in Milk Products Keywords
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