, Volume 36, Issue 8, pp 773–781 | Cite as

Conjugated linoleic acid supplementation in humans—metabolic effects

  • Annika SmedmanEmail author
  • Bengt Vessby


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.


Linoleic Acid Conjugate Linoleic Acid Desaturase Activity Conjugate Linoleic Acid Supplementation Sagittal Abdominal Diameter 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.




Apo A-I

apolipoprotein A-I

Apo B

apolipoprotein 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


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  1. 1.
    Chin, S.F., Liu, W., Storkson, J.M., Ha, L.A., and Pariza, M.W. (1992) Dietary Sources of Conjugated Dienoic Isomers of Linoleic Acid, a Newly Recognized Class of Anticarcinogens, J. Food Composition Anal. 5, 185–197.CrossRefGoogle Scholar
  2. 2.
    Belury, M.A. (1995) Conjugated Dienoic Linoleate: A Polyunsaturated Fatty Acid with Unique Chemoprotective Properties, Nutr. Rev. 53, 83–89.PubMedCrossRefGoogle Scholar
  3. 3.
    MacDonald, H.B. (2000) Conjugated Linoleic Acid and Disease Prevention: A Review of Current Knowledge, J. Am. Coll. Nutr. 19, 111S-118S.PubMedGoogle Scholar
  4. 4.
    Zambell, K.L., Keim, N.L., Van Loan, M.D., Gale, B., Benito, P., Kelley, D.S., and Nelson, G.J. (2000) Conjugated Linoleic Acid Supplementation in Humans: Effects on Body Composition and Energy Expenditure, Lipids 35, 777–782.PubMedGoogle Scholar
  5. 5.
    Medina, E.A., Horn, W.F., Keim, N.L., Havel, P.J., Benito, P., Kelley, D.S., Nelson, G.J., and Erickson, K.L. (2000) Conjugated Linoleic Acid Supplementation in Humans: Effects on Circulating Leptin Concentrations and Appetite, Lipids 35, 783–788.PubMedGoogle Scholar
  6. 6.
    Blankson, H., Stakkestad, J.A., Fagertun, H., Thom, E., Wadstein, J., and Gudmundsen, O. (2000) Conjugated Linoleic Acid Reduces Body Fat Mass in Overweight and Obese Humans, J. Nutr. 130, 2943–2948.PubMedGoogle Scholar
  7. 7.
    Basu, S., Smedman, A., and Vessby, B. (2000) Conjugated Linoleic Acid Induces Lipid Peroxidation in Humans, FEBS Lett. 468, 33–36.PubMedCrossRefGoogle Scholar
  8. 8.
    Forslund, A.H., Johansson, A.G., Sjodin, A., Bryding, G., Ljunghall, S., and Hambraeus, L. (1996) Evaluation of Modified Multicompartment Models to Calculate Body Composition in Healthy Males, Am. J. Clin. Nutr. 63, 856–862.PubMedGoogle Scholar
  9. 9.
    Boberg, M., Croon, L.B., Gustafsson, I.-B., and Vessby, B. (1985) Platelet Fatty Acid Composition in Relation to Fatty Acid Composition in Plasma and Serum Lipoprotein Lipids in Healthy Subjects with Special Reference to the Linoleic Acid Pathway, Clin. Sci. 68, 581–587.PubMedGoogle Scholar
  10. 10.
    Havel, R.J., Eder, H.A., and Bragdon, J.H. (1955) The Determination and Chemical Composition of Ultracentrifugally Separated Lipoproteins in Human Serum, J. Clin. Invest. 34, 1345–1353.PubMedCrossRefGoogle Scholar
  11. 11.
    Seigler, L., and Wu, W.T. (1981) Separation of Serum High-Density Lipoprotein for Cholesterol Determination: Ultra-Centrifugation vs. Precipitation with Sodium Phosphotungstate and Magnesium Chloride, Clin. Chem. 27, 838–841.PubMedGoogle Scholar
  12. 12.
    Pariza, M.W., Park, Y., and Cook, M.E. (2001) The Biologically Active Isomers of Conjugated Linoleic Acid, Prog. Lipid Res. 40, 283–298.PubMedCrossRefGoogle Scholar
  13. 13.
    DeLany, J.P., and West, D.B. (2000) Changes in Body Composition with Conjugated Linoleic Acid, J. Am. Coll. Nutr. 19, 487S-493S.PubMedGoogle Scholar
  14. 14.
    Park, Y., Albright, K.J., Liu, W., Storkson, J.M., Cook, M.E., and Pariza, M.W. (1997) Effect of Conjugated Linoleic Acid on Body Composition in Mice, Lipids 32, 853–858.PubMedCrossRefGoogle Scholar
  15. 15.
    Benito, P., Nelson, G.J., Kelley, D.S., Bartolini, G., Schmidt, P.C., and Simon, V. (2001) The Effect of Conjugated Linoleic Acid on Plasma Lipoproteins and Tissue Fatty Acid Composition in Humans, Lipids 36, 229–236.PubMedGoogle Scholar
  16. 16.
    de Deckere, E.A., van Amelsvoort, J.M., McNeill, G.P., and Jones, P. (1999) Effects of Conjugated Linoleic Acid (CLA) Isomers on Lipid Levels and Peroxisome Proliferation in the Hamster, Br. J. Nutr. 82, 309–317.PubMedGoogle Scholar
  17. 17.
    Lee, K.N., Kritchevsky, D., and Pariza, M.W. (1994) Conjugated Linoleic Acid and Atherosclerosis in Rabbits, Atherosclerosis 108, 19–25.PubMedCrossRefGoogle Scholar
  18. 18.
    Nicolosi, R.J., Rogers, E.J., Kritchevsky, D., Scimeca, J.A., and Huth, P.J. (1997) Dietary Conjugated Linoleic Acid Reduces Plasma Lipoproteins and Early Aortic Atherosclerosis in Hypercholesterolemic Hamsters, Artery 22, 266–277.PubMedGoogle Scholar
  19. 19.
    Gavino, V.C., Gavino, G., Leblanc, M.J., and Tuchweber, B. (2000) An Isomeric Mixture of Conjugated Linoleic Acids but Not Pure cis-9,trans-11-Octadecadienoic Acid Affects Body Weight Gain and Plasma Lipids in Hamsters, J. Nutr. 130, 27–29.PubMedGoogle Scholar
  20. 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
  21. 21.
    Loskutoff, D.J., and Samad, F. (1998) The Adipocyte and Hemostatic Balance in Obesity: Studies of PAI-1, Arterioscler. Thromb. Vasc. Biol. 18, 1–6.PubMedGoogle Scholar
  22. 22.
    Alessi, M.C., Peiretti, F., Morange, P., Henry, M., Nalbone, G., and Juhan-Vague, I. (1997) Production of Plasminogen Activator Inhibitor 1 by Human Adipose Tissue: Possible Link Between Visceral Fat Accumulation and Vascular Disease, Diabetes 46, 860–867.PubMedGoogle Scholar
  23. 23.
    Folsom, A.R., Qamhieh, H.T., Wing, R.R., Jeffery, R.W., Stinson, V.L., Kuller, L.H., and Wu, K.K. (1993) Impact of Weight Loss on Plasminogen Activator Inhibitor (PAI-1), Factor VII, and Other Hemostatic Factors in Moderately Overweight Adults, Arterioscler. Thromb. 13, 162–169.PubMedGoogle Scholar
  24. 24.
    Benito, P., Nelson, G.J., Kelley, D.S., Bartolini, G., Schmidt, P.C., and Simon, V. (2001) The Effect of Conjugated Linoleic Acid on Platelet Function, Platelet Fatty Acid Composition, and Blood Coagulation in Humans, Lipids 36, 221–227.PubMedGoogle Scholar
  25. 25.
    Banni, S., Angioni, E., Casu, V., Melis, M.P., Carta, G., Corongiu, F.P., Thompson, H., and Ip, C. (1999) Decrease in Linoleic Acid Metabolites as a Potential Mechanism in Cancer Risk Reduction by Conjugated Linoleic Acid, Carcinogenesis 20, 1019–1024.PubMedCrossRefGoogle Scholar
  26. 26.
    Li, Y., and Watkins, B.A. (1998) Conjugated Linoleic Acids Alter Bone Fatty Acid Composition and Reduce ex Vivo Prostaglandin E2 Biosynthesis in Rats Fed n−6 or n−3 Fatty Acids, Lipids 33, 417–425.PubMedCrossRefGoogle Scholar
  27. 27.
    Belury, M.A., and Kempa-Steczko, A. (1997) Conjugated Linoleic Acid Modulates Hepatic Lipid Composition in Mice, Lipids 32, 199–204.PubMedCrossRefGoogle Scholar
  28. 28.
    Lee, K.N., Pariza, M.W., and Ntambi, J.M. (1998) Conjugated Linoleic Acid Decreases Hepatic Stearoyl-CoA Desaturase mRNA Expression, Biochem. Biophys. Res. Commun. 248, 817–821.PubMedCrossRefGoogle Scholar
  29. 29.
    Bretillon, L., Chardigny, J.M., Gregoire, S., Berdeaux, O., and Sebedio, J.L. (1999) Effects of Conjugated Linoleic Acid Isomers on the Hepatic Microsomal Desaturation Activities in Vitro, Lipids 34, 965–969.PubMedCrossRefGoogle Scholar
  30. 30.
    Pan, D.A., Lillioja, S., Milner, M.R., Kriketos, A.D., Baur, L.A., Bogardus, C., and Storlien, L.H. (1995) Skeletal Muscle Membrane Lipid Composition Is Related to Adiposity and Insulin Action, J. Clin. Invest. 96, 2802–2808.PubMedGoogle Scholar
  31. 31.
    Borkman, M., Storlien, L.H., Pan, D.A., Jenkins, A.B., Chisholm, D.J., and Campbell, L.V. (1993) The Relation Between Insulin Sensitivity and the Fatty Acid Composition of Skeletal-Muscle Phospholipids, N. Engl. J. Med. 328, 238–244.PubMedCrossRefGoogle Scholar
  32. 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
  33. 33.
    Kavanaugh, C.J., Liu, K.L., and Belury, M.A. (1999) Effect of Dietary Conjugated Linoleic Acid on Phorbol Ester-Induced PGE2 Production and Hyperplasia in Mouse Epidermis, Nutr. Cancer 33, 132–138.PubMedCrossRefGoogle Scholar
  34. 34.
    Jiang, J., Wolk, A., and Vessby, B. (1999) Relation Between the Intake of Milk Fat and the Occurrence of Conjugated Linoleic Acid in Human Adipose Tissue, Am. J. Clin. Nutr. 70, 21–27.PubMedGoogle Scholar
  35. 35.
    Fritsche, J., and Steinhart, H. (1998) Amounts of Conjugated Linoleic Acid (CLA) in German Foods and Evaluation of Daily Intake, Z. Lebensm. Unters. Forsch. A 206, 77–82.CrossRefGoogle Scholar
  36. 36.
    Herbel, B.K., McGuire, M.K., McGuire, M.A., and Shultz, T.D. (1998) Safflower Oil Consumption Does Not Increase Plasma Conjugated Linoleic Acid Concentrations in Humans, Am. J. Clin. Nutr. 67, 332–337.PubMedGoogle Scholar
  37. 37.
    Park, Y., Storkson, J.M., Albright, K.J., Liu, W., and Pariza, M.W. (1999) Evidence that the trans-10,cis-12 Isomer of Conjugated Linoleic Acid Induces Body Composition Changes in Mice, Lipids 34, 235–241.PubMedCrossRefGoogle Scholar
  38. 38.
    Baumgard, L.H., Corl, B.A., Dwyer, D.A., Saebo, A., and Bauman, D.E. (2000) Identification of the Conjugated Linoleic Acid Isomer That Inhibits Milk Fat Synthesis, Am. J. Physiol. Regul. Integr. Comp. Physiol. 278, R179-R184.PubMedGoogle Scholar

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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