Conjugated linoleic acid supplementation in humans—metabolic effects
- 684 Downloads
Supplementation with conjugated linoleic acid (CLA) induces a number of physiological effects in experimental animals, including reduced body fat content, decreased aortic lipid deposition, and improved serum lipid profile. Controlled trials on the effects of CLA in humans have hitherto been scarce. The aim of this study was to evaluate the effects of supplementation with CLA in healthy humans on anthropometric and metabolic variables and on the fatty acid composition of serum lipids and thrombocytes. Fifty-three healthy men and women, aged 23–63 yr, were randomly assigned to supplementation with CLA (4.2 g/d) or the same amount of olive oil during 12 wk in a double-blind fashion. The proportion of body fat decreased (−3.8%, P<0.001) in the CLA-treated group, with a significant difference from the control group (P=0.050). Body weight, body mass index, and sagittal abdominal diameter were unchanged. There were no major differences between the groups in serum lipoproteins, nonesterified fatty acids, plasma insulin, blood glucose, or plasminogen activator inhibitor 1 (PAI-1). In the CLA group the proportions of stearic, docosatetraenoic, and docosapentaenoic acids increased in serum lipids and thrombocytes, while proportions of palmitic, oleic, and dihomoγ-linolenic acids decreased, causing a decrease of the estimated Δ-6 and Δ-9 and an increase in the Δ-5 desaturase activities. These results suggest that supplementation with CLA may reduce the proportion of body fat in humans and that CLA affects fatty acid metabolism. No effects on body weight, serum lipids, glucose metabolism, or PAI-1 were seen.
KeywordsLinoleic Acid Conjugate Linoleic Acid Desaturase Activity Conjugate Linoleic Acid Supplementation Sagittal Abdominal Diameter
- Apo A-I
- Apo B
body mass index
conjugated linoleic acid
high density lipoprotein
low density lipoprotein
plasminogen activator inhibitor 1
peroxisome proliferator activator receptor
very low density lipoprotein
Unable to display preview. Download preview PDF.
- 20.Houseknecht, K.L., Vanden Heuvel, J.P., Moya-Camarena, S.Y., Portocarrero, C.P., Peck, L.W., Nickel, K.P., and Belury, M.A. (1998) Dietary Conjugated Linoleic Acid Normalizes Impaired Glucose Tolerance in the Zucker Diabetic Fatty fa/fa Rat [published erratum appears in Biochem. Biophys. Res. Commun. 1998 Jun 29;247(3), 911], Biochem. Biophys. Res. Commun. 244, 678–682.PubMedCrossRefGoogle Scholar
- 32.Öhrvall, M., Berglund, L., Salminen, I., Lithell, H., Aro, A., and Vessby, B. (1996) The Serum Cholesterol Ester Fatty Acid Composition but Not the Serum Concentration of Alpha Tocopherol Predicts the Development of Myocardial Infarction in 50-Year-Old Men; 19 Years Follow-Up, Atherosclerosis 127, 65–71.PubMedCrossRefGoogle Scholar