Nutritional Supplement

Conjugated Linoleic Acid for Sports & Fitness

Also indexed as: CLA, Linoleic Acid (Conjugated), Tonalin
Conjugated Linoleic Acid

Conjugated linoleic acid (CLA) is a slightly altered form of the essential fatty acid linoleic acid.

Why Do Athletes Use It?*

Some athletes say that CLA helps reduce body fat and increase muscle strength and size.

What Do the Advocates Say?*

Research suggests that conjugated linoleic acid (CLA) may help reduce body fat and increase muscle strength and size. There are at least seven human studies (two double-blind and some controlled) showing significant reduction of abdominal obesity and body fat mass in overweight and moderately obese people. However, since most of the studies involved a small number of participants and were short in duration, larger double-blind studies are needed to further document the benefits and mechanisms of action.

Although CLA promotes weight loss, which is good for heart health, it is important to monitor HDL (“good”) cholesterol levels as CLA may reduce them.

How Much Is Usually Taken by Athletes?

CLA is a slightly altered form of the essential fatty acid linoleic acid. Animal research suggests an effect of CLA supplementation on reducing body fat.1,2 Controlled human research has reported that 5.6 to 7.2 grams per day of CLA produces only non-significant gains in muscle size and strength in experienced and inexperienced weight-training men.3,4,5 A double-blind study of a group of trained men and women reported reduced body fat in the upper arm after 12 weeks of supplementation with 1.8 grams per day of CLA.6 Further research using more accurate techniques for measuring body composition is needed to confirm these findings.

References

1. West DB, Delany JP, Camet PM, et al. Effects of conjugated linoleic acid on body fat and energy metabolism in the mouse. Am J Physiol 1998;275:R667-72.

2. Park Y, Albright KJ, Liu W, et al. Effect of conjugated linoleic acid on body composition in mice. Lipids 1997;32:853-8.

3. Ferreira M, Krieder R, Wilson M. Effects of CLA supplementation during resistance training on body composition and strength. J Strength Conditioning Res 1998;11:280.

4. Kreider RB, Ferreira MP, Greenwood M, et al. Effects of conjugated linoleic acid supplementation during resistance training on body composition, bone density, strength, and selected hematological markers. J Strength Cond Res 2002;16:325-34.

5. Lowery LM, Appicelli PA, Lemon PWR. Conjugated linoleic acid enhances muscle size and strength gains in novice bodybuilders. Med Sci Sport Excer 1998;30:S182 [abstract]

6. Thom E, Wadstein J, Gudmundsen O. Conjugated linoleic acid reduces body fat in healthy exercising humans. J Int Med Res 2001;29:392-6.

7. Whigham LD, Watras AC, Schoeller DA. Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr 2007;85:1203–11.

8. den Hartigh LJ. Conjugated Linoleic Acid Effects on Cancer, Obesity, and Atherosclerosis: A Review of Pre-Clinical and Human Trials with Current Perspectives. Nutrients 2019 Feb;11(2):370.

9. Onakpoya IJ, Posadzki PP, Watson LK, 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 2012 Mar;51(2):127–34.

10. Larsen TM, Toubro S, Gudmundsen O, et al. Conjugated linoleic acid supplementation for 1 y does not prevent weight or body fat regain. Am J Clin Nutr 2006 Mar;83(3):606–12.

11. Ebrahimi-Mameghani M, Jamali H, Mahdavi R, et al. Conjugated linoleic acid improves glycemic response, lipid profile, and oxidative stress in obese patients with non-alcoholic fatty liver disease: a randomized controlled clinical trial. Croat Med J 2016 Aug;57(4):331–42.

12. Riserus U, Vessby B, Arnlov J, Basu S. Effects of cis-9,trans-11 conjugated linoleic acid supplementation on insulin sensitivity, lipid peroxidation, and proinflammatory markers in obese men. Am J Clin Nutr 2004;80:279–83.

13. Risérus U, Vessby B, Arner P, et al. Supplementation with trans10cis12-conjugated linoleic acid induces hyperproinsulinaemia in obese men: close association with impaired insulin sensitivity. Diabetologia 2004 Jun;47(6):1016–9.

14. West DB, Delany JP, Camet PM, et al. Effects of conjugated linoleic acid on body fat and energy metabolism in the mouse. Am J Physiol 1998;275:R667-72.

15. Park Y, Albright KJ, Liu W, et al. Effect of conjugated linoleic acid on body composition in mice. Lipids 1997;32:853-8.

16. Ferreira M, Krieder R, Wilson M. Effects of CLA supplementation during resistance training on body composition and strength. J Strength Conditioning Res 1998;11:280.

17. Kreider RB, Ferreira MP, Greenwood M, et al. Effects of conjugated linoleic acid supplementation during resistance training on body composition, bone density, strength, and selected hematological markers. J Strength Cond Res 2002;16:325-34.

18. Lowery LM, Appicelli PA, Lemon PWR. Conjugated linoleic acid enhances muscle size and strength gains in novice bodybuilders. Med Sci Sport Excer 1998;30:S182 [abstract]

19. Thom E, Wadstein J, Gudmundsen O. Conjugated linoleic acid reduces body fat in healthy exercising humans. J Int Med Res 2001;29:392-6.

20. Cesano A, Visonneau S, Scimeca JA, et al. Opposite effects of linoleic acid and conjugated linoleic acid on human prostatic cancer in SCID mice. Anticancer Res 1998;18:1429-34.

21. Thompson H, Zhu Z, Banni S, et al. Morphological and biochemical status of the mammary gland as influenced by conjugated linoleic acid: implication for a reduction in mammary cancer risk. Cancer Res 1997;57:5067-72.

22. Ip C. Review of the effects of trans fatty acids, oleic acid, n-3 polyunsaturated fatty acids, and conjugated linoleic acid on mammary carcinogenesis in animals. Am J Clin Nutr 1997;66(suppl):1523S-29S [review].

23. Parodi PW. Cows' milk fat components as potential anticarcinogenic agents. J Nutr 1997;127:1055-60 [review].

24. Cesano A, Visonneau S, Scimeca JA, et al. Opposite effects of linoleic acid and conjugated linoleic acid on human prostatic cancer in SCID mice. Anticancer Res 1998;18:1429-34.

25. Thompson H, Zhu Z, Banni S, et al. Morphological and biochemical status of the mammary gland as influenced by conjugated linoleic acid: implication for a reduction in mammary cancer risk. Cancer Res 1997;57:5067-72.

26. Ip C. Review of the effects of trans fatty acids, oleic acid, n-3 polyunsaturated fatty acids, and conjugated linoleic acid on mammary carcinogenesis in animals. Am J Clin Nutr 1997;66(suppl):1523S-29S [review].

27. Parodi PW. Cows' milk fat components as potential anticarcinogenic agents. J Nutr 1997;127:1055-60 [review].

28. Herbel BK, McGuire MK, McGuire MA, et al. Safflower oil consumption does not increase plasma conjugated linoleic acid concentrations in humans. Am J Clin Nutr 1998;67:332-7.

29. Gaullier JM, Halse J, Hoye K, et al. Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans. Am J Clin Nutr 2004;79:1118–25.

30. Smedman A, Basu S, Jovinge S, Fredrikson GN, Vessby B. Conjugated linoleic acid increased C-reactive protein in human subjects. Br J Nutr 2005;94:791-5.

31. Taylor JS, Williams SR, Rhys R, et al. Conjugated linoleic acid impairs endothelial function. Arterioscler Thromb Vasc Biol2006;26:307-12.

32. Moloney F, Yeow TP, Mullen A, et al. Conjugated linoleic acid supplementation, insulin sensitivity, and lipoprotein metabolism in patients with type 2 diabetes mellitus. Am J Clin Nutr 2004;80:887-95.

33. Riserus U, Vessby B, Arnlov J, Basu S. Effects of cis-9,trans-11 conjugated linoleic acid supplementation on insulin sensitivity, lipid peroxidation, and proinflammatory markers in obese men. Am J Clin Nutr 2004;80:279–83.

34. Whigham LD, O'Shea M, Mohede IC, et al. Safety profile of conjugated linoleic acid in a 12-month trial in obese humans. Food Chem Toxicol 2004 Oct;42(10):1701-9.

35. Eyjolfson V, Spriet LL, Dyck DJ. Conjugated linoleic acid improves insulin sensitivity in young, sedentary humans. Med Sci Sports Exerc 2004;36:814-20.

36. Thom E. A pilot study with the aim of studying the efficacy and tolerability of Tonalin CLA on the body composition in humans. Lillestrom, Norway: Medstat Research Ltd., July 1997 [unpublished].

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2024.