Lipids

, Volume 36, Issue 8, pp 773–781

Conjugated linoleic acid supplementation in humans—metabolic effects

Article

DOI: 10.1007/s11745-001-0784-7

Cite this article as:
Smedman, A. & Vessby, B. Lipids (2001) 36: 773. doi:10.1007/s11745-001-0784-7

Abstract

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.

Abbreviations

Apo(a)

apolipoprotein(a)

Apo A-I

apolipoprotein A-I

Apo B

apolipoprotein B

BMI

body mass index

CLA

conjugated linoleic acid

HDL

high density lipoprotein

LDL

low density lipoprotein

PAI-1

plasminogen activator inhibitor 1

PPAR

peroxisome proliferator activator receptor

VLDL

very low density lipoprotein

Copyright information

© AOCS Press 2001

Authors and Affiliations

  1. 1.Unit for Clinical Nutrition Research, Department of Public Health and Caring Sciences/GeriatricsUppsala UniversityUppsalaSweden

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