Conjugated linoleic acid (CLA) and functional food?

Conjugated linoleic acid (CLA) is found naturally in many animal products e specially those from ruminant sources. CLA can also be synthesized in the l aboratory by isomerisation of linoleic acid. While the "natural" isomer is the 9c, 11t-, synthetic mixtures contain mainly two isomers, the 9c, 11t- a nd the 10t, 12c-18:2. Many experiments carried out on animal models mainly using the synthetic isomers have shown different health benefits (anticarci nogenic, antiatherosclerotic effects, modulation of body composition...) wh ile most of the studies carried out on human concern the effects of CLA on body composition. At the moment, the data on the effects on body composition in human seem to indicate a potential benefit but are still controversial. Furthermore even if anticarcinogenic effects have been demonstrated in animals, studies so for corned out on human have failed to demonstrate a relation between CLA a nd breast cancer and very few data dealing with the safety of using CLA in long term feeding studies have been so far published. Consequently, before using CLA in functional food, it will be necessary to obtain more human dat a and to be able to guarantee the safety of these fatty acids in order to p rotect the consumer.