Milk Lipids | Conjugated Linoleic Acid

There is growing consumer recognition that in addition to providing essential nutrients, foods also contain components that may benefit health maintenance and aid in the prevention of chronic diseases. One of these functional food components is rumenic acid (RA), the cis-9, trans-11 isomer of conjugated linoleic acid (CLA). Dairy products are the major source of CLA in human diets and its presence relates to rumen biohydrogenation of polyunsaturated fatty acids found naturally in grains and forages. Through modification of the diets of dairy cows and selection of cows with the highest milk RA content, it is possible to produce milk that is substantially enriched with RA. Vaccenic acid (trans-11 18:1) is also present in milk fat and its contribution as a functional food component of milk must also be considered because it is the precursor for the endogenous synthesis of RA in both cows and humans. When consumed as a natural food component, RA has anticarcinogenic and antiatherogenic effects in biomedical studies with animal models; however, extending results to investigations of the prevention of chronic diseases in humans is difficult. Nevertheless, dairy products enriched with RA represent functional foods that offer potential to benefit human health and prevent chronic diseases.