CLAs in Animal Source Foods: Healthy Benefits for Consumers

Conjugated linoleic acid (CLA) is a group of polyunsaturated fatty acids that exist as positional and stereo-isomers of octadecadienoate (18:2). Among these isomers, the most studied two isomers are cis 9, trans 11-CLA and trans 10, cis 12- CLA due to their biological effects. CLA can be naturally synthesized in the rumen of ruminant animals by bacteria Butyrivibrio fibrisolvens via the Δ-9- desaturase of trans 11 octadecanoic acid pathway. The major dietary sources of CLA are represented by meat and milk from ruminant animals. Although references to CLA can be traced back to the 1950s, current interest in the health benefits of CLA started in the late 1980s, after it was identified as the anticarcinogenic component present in fried ground beef. Since then, an extensive literature has documented the anticarcinogenic effects of CLA. In addition, there is some evidence that CLA is also anti-atherosclerotic, has beneficial effects on type 2 diabetes, and may play a key role in helping to regulate body fat. The fact that the richest natural sources of CLA, meat and dairy products, are consumed by people worldwide has very interesting implications for public health.