In brief

• CLA are a family of polyunsaturated fatty acid naturally found in meat and dairy products
• Benefits associated with CLA supplementation include
  • enhancing exercise performance,
  • promoting recovery and adaptation from training,
  • promoting fat loss,
  • improving bone health,
  • strengthening immune defence, and
  • providing protection against several lifestyle-related diseases
• Intakes of CLA of approximately 3 g per day or above are required to obtain these benefits, which is most easily achieved by supplement form rather than through dietary sources

Background

CLA are a family of polyunsaturated fatty acids (PUFAs) derived from the omega-6 fatty acid linoleic acid and is a naturally occurring essential fat. A fatty acid is simply a small molecule that acts as a fuel source, or a building block for cells, whereas the term “essential” refers to the fact that the enzymes necessary for their production are absent from the human body. Therefore, our intake of CLA is through the foods that we eat, or otherwise achieved by supplementation. For a more detailed account of the structure of fatty acids and PUFAs, read our article Healthy fats, fish oils & omega-3 supplementation’.

CLA are formed by bacterial reactions occurring in the stomach of ruminant animals that change the chemical structure of linoleic acid. Ruminant animals are those that consume a plant-based diet, with the major difference being the presence of a four-compartment stomach e.g. cattle, goats, sheep and so on. Linoleic acid is a fatty acid containing 18 carbon atoms. Double bonds are located at the 9th and 12th carbons and both of these double bonds are in what is known as a cis configuration (cis-9, cis-12). The reactions produce various cis- and trans- CLA isomers, the most commonly known (for their health and performance benefits) are the c-9, t-11 and the t-10, c-12 CLA isomers.

It is generally advised to reduce, if not eliminate trans fats from our daily diets (typically found in foods such as margarines and processed, fried or fast foods). However, unlike these processed trans fats that are associated with increased risk of numerous disease states such as cardiovascular disease, stroke, and type 2 diabetes, CLA is a naturally-occurring trans fat that is associated with several health and performance-enhancing properties. Dietary sources of CLA are mainly from the meat of ruminant animals (e.g. beef, lamb) and dairy products (e.g. milk, yoghurt), and are particularly rich in the meats of grass-fed animals.

What does the research say?

Current research supports the use of CLA supplementation to improve bone health, strengthen immune defences, help protect against several lifestyle-related diseases, and decrease body weight (particularly fat mass). Accumulating evidence also describes a role in supporting training adaptation and recovery, and facilitating enhanced sports performance.

Sports performance, training adaptation and recovery, CLA supplementation promotes an increase in mitochondrial content and metabolism¹ (the “powerhouse” of muscle cells involved in energy production and use), facilitating more fat burning potential² and sparing carbohydrate stores for more intensive workouts. Furthermore, CLA supplementation helps to reduce lactate accumulation during exercise³ (a by-product of carbohydrate use), which may help delay fatigue. This likely explains the enhanced endurance performance (increased distance and/or duration performed) following CLA supplementation³.

CLA supplementation also assists muscle building and strength development. For instance, CLA supplementation (6 g/day) during five weeks of strength training led to larger increases in both upper and lower body strength (measured by means of maximum weight lifted for bench press and leg press, respectfully), compared to individuals not being supplemented with CLA⁴. CLA provides a more anabolic (muscle-building) environment by enhancing insulin action⁵ and increasing testosterone levels⁶ during and/or after training. CLA supplementation allows for faster and more efficient recovery following training by decreasing catabolism (muscle-breakdown) by increasing antioxidant support⁷ and/or decreasing inflammation⁸.

Bone health Weight loss is generally associated with negative effects on bone health by reducing bone mineral density, a risk factor for osteoporosis. However CLA supplementation may increase the total bone density, ⁹ while also supporting decreases in body weight. The benefit of CLA supplementation on bone mass may be further enhanced when used in combination with exercise¹⁴, which is also known to increase bone mass.

General health & immunity CLA supplementation enhances immune defences and increases the protection against foreign substances such as airborne allergens¹⁰. Additionally CLA supplementation shows some benefits in inflammatory bowel disease (IBD), by delaying and/or reducing levels of inflammation¹¹. Finally, CLA supplementation may also help protect against several chronic disease states including cardiovascular disease, type 2 diabetes, and several cancers by decreasing inflammation⁷, enhancing insulin action and blood sugar control⁵, increasing antioxidant levels⁸ and regulating blood lipid levels (triglycerides¹² and total cholesterol:HDL-cholesterol (“good fats”) ratio¹³).

Body composition An area of intense interest in CLA supplementation is for the potential role in improving body composition by reducing fat mass. In fact, CLA supplementation enhances body tone and promotes increases in muscle mass. For example, in the study described above, individuals supplemented with CLA (6 g/day) combined with whey protein and creatine showed double the gains in muscle mass compared to those in the non-CLA groups following five weeks of resistance training⁴. However, increases in muscle mass have been reported in combination with and without exercise⁷.

CLA (particularly the t-10, c-12 isomer) is most renowned for an ability to promote weight and fat loss and facilitate decreases in body circumferences (i.e. waist and hips)⁵.  Six weeks of CLA supplementation (of 3.6 g/day) significantly reduced body weight and fat mass, with further reductions shown when CLA supplementation was combined with endurance exercise⁵. This is attributable to CLAs’ ability to (i) decrease appetite⁷ (therefore promoting adherence to calorie-restrictive diets); (ii) increase energy (fat) burning²; (iii) reduce fat storage ¹⁴; (iv) decrease the production of new fat cells¹⁵; and/or (v) promote cell death of fat cells¹⁵.

What does this mean in practice?

In the Western diet, dietary intakes of CLA typically only reach approximately 0.2 g/day¹⁶, whereas the quantity of CLA associated with health and/or performance benefits is in the range of 3-4 g/day)¹⁷. To this end, consuming CLA in supplement form as an adjunct to a healthy, whole foods-based diet is likely to offer the following benefits:

• Weight loss diets: promote weight/fat loss preferentially while following calorie-restricted diets
• Endurance training: promote increased fat burning as a fuel during exercise performance, helping to spare muscle carbohydrate stores for more intense exercise bouts
• Sprint/power/strength athletes: promote decreased body fat and support increases in muscle mass, thereby improving body composition and power-to-mass ratio critical for performance
• Ball-sport athletes/gym-based training: promotes recovery and adaptation from training by helping to reduce the overall inflammatory response to intense activity
• Illness: helps support the immune system to help protect the body against illness

CLA supplements at ROS Nutrition

The dose-response effect of CLA supplementation is a key factor that is overlooked by many consumers. Simply put, if you are consuming less than the threshold of 3 g per day of CLA in supplement form, then you are unlikely to observe any of the above effects¹⁷. While many supplemental forms of CLA are present on the market, at ROS Nutrition our recommended daily dose and timing reflects these latest scientific findings.

In addition, ROS Nutrition uses only the finest quality CLARINOL^® CLA in its naturally-occurring Triglyceride [TG] form, produced using high quality and safety -controlled standards, which ensures only the highest possible concentration of beneficially-active CLA isomers in the product. This is important as CLA in the TG form is better digested and absorbed by the body, compared to the Ethylester [EE] form of CLA¹⁸. CLARINOL^® CLA is a safe and natural weight management ingredient, derived from safflower. CLARINOL^® CLA should not replace a healthy, balanced diet however it can be consumed continuously as directed as part of a healthy diet and lifestyle plan. Studies have shown CLARINOL^® CLA to be safe, with no adverse effects reported at the recommended doses¹⁸. CLARINOL^® CLA is gluten-free, suitable for vegetarians and contains no artificial colours, flavours or preservatives.

Find CLA at ROS Nutrition

Further reading

• Vaughan RA, Garcia-Smith R, Bisoffi M, Conn CA & Trujillo KA (2012) Conjugated linoleic acid or omega 3 fatty acids increase mitochondrial biosynthesis and metabolism in skeletal muscle cells. Lipids Health Dis, 11, 142-151.
• Mizunova W, Haramizu S, Shibakusa T, Okabe Y & Fushiki T (2005) Dietary conjugated linoleic acid increases endurance capacity and fat oxidation in mice during exercise. Lipids, 40 (3), 265-271.
• Kim JH, Kim J & Park Y (2012) trans-10, cis-12 conjugated linoleic acid enhances endurance capacity by increasing fatty acid oxidation and reducing glycogen utilization in mice. Lipids, 47 (9), 855-863.
• Cornish SM, Candow DG, Jantz NT, Chilibeck PD, Little JP, Forbes S, Abeysekara S & Zello GA (2009) Conjugated linoleic acid combined with creatine monohydrate and whey protein supplementation during strength training. Int J Sports Nutr Exer Metab, 19 (1), 79-96.
• Colakoglu S, Colakoglu M, Taneli F, Cetinoz F & Turkmen M (2006) Cumulative effects of conjugated linoleic acid and exercise on endurance development, body composition, serum leptin and insulin levels. J Sports Med Phys Fitness, 46 (4), 570-577.
• Macaluso F, Morici G, Catanese P, Ardizzone Nm, Marino Gammazzza A, Bonsignore G, Lo Guidice G, Stampone T, Barone R, Farina F & Di Felice V (2012) Effect of conjugated linoleic acid on testosterone levels in vitro and in vivo after an acute bout of resistance exercise. J Strength Cond Res, 26 (6), 1667-1674.
• Bhattacharya A, Rahman MM, Sun D, Lawrence R, Meija W, McCarter R, O’Shea M & Fernandes G (2005) The combination of dietary conjugated linoleic acid and treadmill exercise lowers gain in body fat mass and enhances lean body mass in high fat-fed male Balb/C mice. J Nutr, 135 (5), 1124-1130.
• Hennessy AA, Ross RP, Devery R & Stanton C (2011) The health promoting properties of the conjugated isomers of α-linoleic acid. Lipids, 46, 105-119.
• Banu J, Bhattacharya A, Rahman M & Fernandes G (2008) Beneficial effects of conjugated linoleic acid and exercise on bone of middle-aged female mice. J Bone Miner Metab, 26 (5), 436-445.
• Turpeinen AM, Ylönen N, von Willebrand E, Basu S & Aro A (2008) Immunological and metabolic effects of cis-9, trans-11-conjugated linoleic acid in subjects with birch pollen allergy. Br J Nutr, 100, 112-119.
• Bassaganya-Riera J & Honteciallas R (2006) CLA and n-3 PUFA differentially modulate clinical activity and colonic PPAR-responsive gene expression in a pig model of experimental IBD. Clin Nutr, 25 (3), 454-465.
• Bouthegourd JC, Even PC, Gripois D, Tiffon B, Blouquit MF, Roseau S, Lutton C, Tomé D & Martin JC (2002) A CLA mixture prevents body triglyceride accumulation without affecting energy expenditure in Syrian hamsters. J Nutr, 132 (9), 2682-2689.
• Wanders AJ, Brouwer IA, Siebelink E & Katan MB (2010) Effect of a high intake of conjugated linoleic acid on lipoprotein levels in healthy human subjects. Plos One, 5 (2), 1-7.
• Brown JM, Boysen MS, Chung S, Fabiyi O, Morrison RF, Mandrup S & McIntosh MK (2004) Conjugated linoleic acid induces human adipocyte delipidation. J Biol Chem, 279 (25), 26735-26747.
• Fischer-Posovszky P, Kukulus V, Zulet MA, Debatin KM & Wabitsch M (2007) Conjugated linoleic acids promote human fat cell apoptosis. Horm Metab Res, 39, 186-191.
• Ritzenthaler KL, McGuire MK, Falen R, Shultz TD, Dasgupta N & McGuire MA (2001) Estimation of conjugated linoleic acid intake by written dietary assessment methodologies underestimates actual intake evaluated by food duplicate methodology. J Nutr, 131 (5), 1548-1554.
• 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, 1203-1211.
• Gaullier JM, Halse J, Hoivik HO, Hoye K, Syvertsen C, Nutminiemi M, Hassfeld C, Einerhand A, O’Shea M & Gudmundsen O (2007) Six months supplementation with conjugated linoleic acid induces regional-specific fat mass decreases in overweight and obese. Br J Nutr, 97 (3), 550-560.