Efficacy and safety of dietary supplements containing CLA for the treatment of obesity

evidence from animal and human studies

  1. Arne Astrup
  1. Department of Human Nutrition, Center for Advanced Food Studies, The Royal Veterinary and Agricultural University, DK-1958 Frederiksberg C, Denmark
  1. 1To whom correspondence should be addressed. e-mail: tml{at}kvl.dk

Abstract

Dietary supplements containing conjugated linoleic acid (CLA) are widely promoted as weight loss agents available over the counter and via the Internet. In this review, we evaluate the efficacy and safety of CLA supplementation based on peer-reviewed published results from randomized, placebo-controlled, human intervention trials lasting more than 4 weeks. We also review findings from experimental studies in animals and studies performed in vitro. CLA appears to produce loss of fat mass and increase of lean tissue mass in rodents, but the results from 13 randomized, controlled, short-term (<6 months) trials in humans find little evidence to support that CLA reduces body weight or promotes repartitioning of body fat and fat-free mass in man. However, there is increasing evidence from mice and human studies that the CLA isomer trans-10, cis-12 may produce liver hypertrophy and insulin resistance via a redistribution of fat deposition that resembles lipodystrophy. CLA also decreases the fat content of both human and bovine milk.

In conclusion, although CLA appears to attenuate increases in body weight and body fat in several animal models, CLA isomers sold as dietary supplements are not effective as weight loss agents in humans and may actually have adverse effects on human health.

Footnotes

  • Published, JLR Papers in Press, August 16, 2003. DOI 10.1194/jlr.R300011-JLR200

    • Abbreviations

    • CLA, conjugated linoleic acid

    • c9,t11, cis-9, trans-11

    • DXA, dual-energy X-ray absorptiometry

    • FFM, fat-free mass

    • FM, fat mass

    • MUFA, monounsaturated fatty acid

    • SCD1, stearoyl-CoA desaturase 1

    • SFA, saturated fatty acid

    • t10,c12, trans-10, cis-12

    • TG, triglyceride

  • Received July 17, 2003.
  • Revision received August 13, 2003.
View this article with LENS beta
| Table of Contents

This Article

  1. First Published on August 16, 2003, doi: 10.1194/jlr.R300011-JLR200 The Journal of Lipid Research, 44, 2234-2241.
  1. » AbstractFree
  2. Full TextFree
  3. Full Text (PDF)Free
  4. All Versions of this Article:
    1. R300011-JLR200v1
    2. 44/12/2234 most recent

Classifications

Current Issue

  1. September 2015, 56 (9)
  1. Current Issue
  1. Alert me to new issues of The Journal of Lipid Research