Numerous supplements containing conjugated linoleic acid (CLA) are presently being promoted for body weight reduction. The aim of this systematic review is to evaluate the evidence for or against the long-term efficacy of CLA.
Electronic searches were conducted to identify relevant randomized clinical trials (RCTs). No restrictions in age, time, or language were imposed. Studies had to be at least 6 months in duration. Three reviewers independently determined the eligibility of studies. Two reviewers independently extracted data and assessed the reporting quality of all RCTs.
Fifteen RCTs were identified, and seven were included. Four of the included RCTs had serious flaws in the reporting of their methodology. A meta-analysis revealed a statistically significant difference in weight loss favouring CLA over placebo (mean difference: −0.70 kg; 95% confidence interval: −1.09, −0.32). Our meta-analysis also revealed a small significant difference in fat loss favouring CLA over placebo (MD: −1.33 kg; 95% CI: −1.79, −0.86; I 2 = 54%). The magnitude of these effects is small, and the clinical relevance is uncertain. Adverse events included constipation, diarrhea, and soft stools.
The evidence from RCTs does not convincingly show that CLA intake generates any clinically relevant effects on body composition on the long term.
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Ogden CL, Yanovski SZ, Carroll MD, Flegal KM (2007) The epidemiology of obesity. Gastroentorology 132:2087–2102
Belury M (2002) Dietary conjugated linoleic acid in health: physiological effects and mechanisms of action. Ann Rev Nutr 22:505–531
Chin SF, Liu W, Storkson JM, Ha YL, Pariza MW (1992) Dietary sources of conjugated dienoic isomers of linoleic acid, a newly recognized class of anticarcinogens. J Food Compos Anal 5:185–197
Whigham LD, Watras AC, Schoeller DA (2007) Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr 85(5):1203–1211
Brown J, McIntosh M (2003) Conjugated linoleic acid in humans: regulation of adiposity and insulin sensitivity. J Nutr 133:3041–3046
Mirand PP, Arnal-Bagnard MA, Mosoni L et al (2004) Cis-9, trans-11 and trans-10, cis-12 conjugated linoleic acid isomers do not modify body composition in adult sedentary or exercised rats. J Nutr 134(9):2263–2269
Baddini FA, Fernandes PA, Ferreria da Costa N, Gonçalves RB (2009) Conjugated linoleic acid (CLA): effect modulation of body composition and lipid profile. Nutr Hosp 24(4):422–428
Salas-Salvadó J, Márquez-Sandoval F, Bulló M (2006) Conjugated linoleic acid intake in humans: a systematic review focussing on its effect on body composition, glucose, and lipid metabolism. Cri Rev Food Sci Nutr 46:479–488
Moher D, Schulz KF, Altman DG (2001) The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials. Lancet 357(9263):1191–1194
Altman DG, Schulz KF, Moher D, Egger M, Davidoff F, Elbourne D, Gøtzsche PC, Lang T (2001) The revised CONSORT statement for reporting randomised trials: explanation and elaboration. Ann Intern Med 134(8):663–694
Review Manager (RevMan) [Computer Program] (2008) Version 5.0. The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen
Gaullier J-M, Halse J, Høye K, Kristiansen K, Fagertun H, Vik H et al (2005) Supplementation with conjugated linoleic acid for 24 months is well tolerated by and reduces body fat mass in healthy, overweight humans. J Nutr 135:778–784
Venkatramanan S, Joseph SV, Chouinard PY, Jacques H, Farnworth ER, Jones PJH (2010) Milk enriched with conjugated linoleic acid fails to alter blood lipids or body composition in moderately overweight, borderline hyperlipidemic individuals. J Am Coll Nutr 29(2):152–159
Von Loeffelholz C, von Loeffelholz B, Jahreis G (1999) Influence of CLA supplementation on body composition and strength in body builders. Vitamins and Additives in Human and Animal Nutrition 238–243
Von Loeffelholz C, Kratzsch J, Jahreis G (2003) Influence of conjugated linoleic acids on body composition and selected serum and endocrine parameters in resistance-trained athletes. Eur J Lipid Sci 105:251–259
Tarnopolsky M, Zimmer A, Jeremy P, Safdar A, Aboud A, Pearce E, et al (2007) Creatine monohydrate and conjugated linoleic acid improve strength and body composition following resistance exercise in older adults. PLoS ONE 2(10):E991. doi:10.1371/journal.pone.0000991
Moya MJ (2007) Use of conjugated linoleic acid in obese children and adolescents. Revista Espanola de Pediatria 63(3):453–457
Close RN, Schoeller DA, Watras AC, Nora EH (2007) Conjugated linoleic acid supplementation alters the 6-mo change in fat oxidation during sleep. Am J Clin Nutr 86:797–804
Syvertsen C, Halse J, Høivik HO, Gaullier J-M, Nurminiemi M, Kristiansen K et al (2007) The effect of 6 months supplementation with conjugated linoleic acid on insulin resistance in overweight and obese. Int J Obes 31(7):1148–1154
Gaullier J-M, Halse J, Høivik HO, Høye K, Syvertsen C, Nurminiemi M et al (2007) Six months supplementation with conjugated linoleic acid induces regional-specific fat mass decreases in overweight and obese. Br J Nutr 97:550–560
Gaullier J-M, Halse J, Høye K, Kristiansen K, Fagertun H, Vik H et al (2004) Conjugated linoleic acid supplementation for 1 year reduces body fat mass in healthy overweight humans. Am J Clin Nutr 79(6):1118–1125
Larsen TM, Toubro S, Gudmundsen O, Astrup A (2006) Conjugated linoleic acid supplementation for 1 year does not prevent weight or body fat regain. Am J Clin Nutr 83(3):606–612
Racine NM, Watras AC, Carrel AL, Allen DB, McVean JJ, Clark RR, et al (2010) Effect of conjugated linoleic acid on body fat accretion in overweight or obese children. Am J Clin Nutr. doi:10.3945/ajcn.2009.28404
Sluijs I, Plantinga Y, de Roos B, Mennen LI, Bots ML (2010) Dietary supplementation with cis-9, trans-11 conjugated linoleic acid and aortic stiffness in overweight and obese adults. Am J Clin Nutr 91(1):175–183
Watras AC, Buchholz AC, Close RN, Zhang Z, Schoeller DA (2007) The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain. Int J Obes 31(3):481–487
Whigham LD, O’Shea M, Mohede ICM, Walaski HP, Atkinson RL (2004) Safety profile of conjugated linoleic acid in a 12-month trial in obese humans. Food Chem Toxicol 42:1701–1709
Christian JG, Tsai AG, Bessesen DH (2010) Interpreting weight loss from lifestyle modification trials: using categorical data. Int J Obes 34(1):207–209
Lachim JM (2000) Statistical Considerations in the Intent-to-Treat Principle. Control Clin Trials 21(3):167–169
Hollis S, Campbell F (1999) What is meant by intention to treat analysis? Survey of published randomised controlled trials. BMJ 319(7211):670–674
(1998) Safflower oil consumption does not increase plasma conjugated linoleic acid concentrations in humans. Am J Clin Nutr 67(2):332–337
Raff M, Tholstrup T, Basu S, Nonboe P, Sørensen MT, Straarup EM (2008) A diet rich in conjugated linoleic acid and butter increases lipid peroxidation but does not affect atherosclerotic, inflammatory or diabetic risk markers in healthy young men. J Nutr 138(3):509–514
Avenell A, Sattar N, Lean M (2007) Management: part I-behaviour change, diet, and activity. In: Sattar N, Lean M (eds) ABC of obesity. Blackwell, Malden, pp 8–11
Yusuf S, Hawken S, Ounpuu S, Bautista L, Franzosi MG, Commerford P (2005) Obesity and the risk of myocardial infarction in 27,000 participants from 52 countries: a case–control study. Lancet 366(9497):1640–1649
Conflict of interest
IJO has a research fellowship funded by GlaxoSmithKline. The funder had no role in any aspect of this project or the preparation of this manuscript. PPP, LKW, LAD, and EE declare no competing interests.
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Onakpoya, I.J., Posadzki, P.P., Watson, L.K. et al. The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: a systematic review and meta-analysis of randomized clinical trials. Eur J Nutr 51, 127–134 (2012). https://doi.org/10.1007/s00394-011-0253-9
- Body weight
- Body fat
- Weight loss
- Fat loss