Effect of conjugated linoleic acid on body composition and plasma lipids in humans: an overview of the literature

• Published in: The American journal of clinical nutrition Vol. 79; no. 3; pp. 352 - 361
• Main Author: Terpstra, Antonius HM
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.03.2004; American Society for Clinical Nutrition; American Society for Clinical Nutrition, Inc
• Subjects: Acids; Adipose Tissue - metabolism; Animals; Biological and medical sciences; Blood Glucose - drug effects; blood lipids; body composition; Body Composition - drug effects; Body fat; Body Weight - drug effects; Conjugated linoleic acid; dietary fat; Energy Metabolism - drug effects; fat intake; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; high density lipoprotein; human nutrition; Humans; Insulin - blood; lean body mass; Leptin - blood; Linoleic Acid - pharmacology; Lipids; Lipids - blood; literature reviews; low density lipoprotein; Meta-Analysis as Topic; Plasma; plasma lipids; triacylglycerols; Vertebrates: anatomy and physiology, studies on body, several organs or systems; weight loss; Conjugated linoleic acid; body composition; plasma lipids; body fat; Human; plasma lipids body fat; Literature; Fat; Lipids; Body composition; Linoleic acid; Blood plasma
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/79.3.352

Studies in mice have indicated that feeding diets containing 0.5-1% conjugated linoleic acid (CLA) considerably reduces body fat. These findings have attracted much interest because of the potential use of CLA as a tool to promote weight loss in humans. Several CLA studies in humans have now been published, and the objective of the present review was to give an overview of these experiments. Most of the studies were done in free-living subjects and were not strictly controlled for nutrient and energy intakes. None of the studies found a significant reduction in body weight, and only 2 studies showed a significant but relatively small body fat-lowering effect. Some studies suggested that CLA may have a tendency to increase lean body mass. Furthermore, there are indications from animal studies that CLA may have effects on plasma lipids. However, only one study in humans showed a significant HDL-cholesterol-lowering effect of CLA; in all the other studies, there were no significant effects on plasma total, LDL-, and HDL-cholesterol concentrations or on plasma triacylglycerol concentrations. Thus, the results of the studies in humans indicate that the effect of CLA on body fat is considerably less than that anticipated from mice studies and that CLA has no major effect on plasma lipids.