Review of the roles of conjugated linoleic acid in health and disease

Dietary fatty acids (FA) are increasingly recognized as major biologic regulators and have properties that relate to health outcomes and disease. Conjugated linoleic acid (CLA) is a generic term denoting a group of isomers of linoleic acid (C18:2, n-6) with a conjugated double bond. CLA has attracted increased research interest because of its health-promoting benefits and biological functions. In a variety of studies, CLA has been shown to impact immune function and has protective effects against cancer, obesity, diabetes, and atherosclerosis in animal studies and in different human cell lines. Studies investigating the mechanisms involved in the biological functions of CLA are emerging with results from both in vivo and in vitro studies. Most of the biological effects have been attributed to the c9,t11-CLA and t10,c12-CLA isomers. The purpose of this review is to discuss the effects of CLA on health and disease and the possible mechanisms for CLA activities.