Conjugated linoleic acid, or CLA, is a naturally occurring member of the linoleic acid family and is found in the milk, cheese and meat of cattle and sheep. Eight different forms of CLA have been identified, and certain forms have more effect than others on health. Since it is a fatty acid, CLA is found more in products that contain half or full fat, such as in the case of whole milk or low-fat milk. Research is establishing functions of CLA on heart disease.
CLA and Weight Loss
Overweight and obesity are risk factors for heart disease. CLA appears to be effective in some research studies, though not all, at decreasing weight and adipose tissue. A study published in the 2009 "Applied Physiology, Nutrition and Metabolism" did a meta-analysis of studies reviewing the effects of CLA on fat-free mass. Fat-free mass is the mass of everything in the body which is not fat. The researchers concluded that CLA did increase fat-free mass which means CLA did not increase fat tissue and likely encouraged an increase in muscle mass instead. The researchers went on to say the increase happens quickly, though is typically small.
CLA and Saturated Fat
CLA may have affect heart disease by preventing the adverse effects of saturated fat. Milk, cheese and meat from pasture-grazed cows contain more CLA than grain-fed cows. Not only this, but milk, cheese and meat are high in saturated fat. High intakes of saturated fat typically contribute to overweight, obesity, high cholesterol and high triglycerides subsequently increasing risk for heart disease. A study published in the 2010 "American Journal of Clinical Nutrition" found a different outcome. Researchers found that CLA in dairy products from cows that were grass-fed tended to offset the adverse effects of saturated fat in dairy products. The researchers looked at the amount of CLA in fat tissue in humans in comparison to the risk of heart attack. Higher levels of CLA were associated with a decreased risk of heart attack.
Hypotensive Properties
CLA has been shown in research to have the ability to lower blood pressure. A study in the October 2004 "Biochemical and Biophysical Research Communications" journal examined the effects of CLA on rats with high blood pressure. The rats were supplemented with CLA for four weeks. After the four weeks, blood pressure had decreased. The researchers think CLA is able to do this by the increased levels of adinopectin. Adinopectin is a hormone that regulates fatty acid metabolism and increases the effectiveness of insulin.
Inhibits Arachiodonic Acid
CLA works for reducing heart disease by inhibiting arachiodonic acid and having an antiplatelet effect. Arachiodonic acid is a polyunsaturated omega-6 fatty acid. High levels of arachiodonic acid found in fat tissue is associated with increased risk of heart attack, explains a study in the November 2004 "Journal of Nutrition." A study published in the 1999 "Biochimica and Biophysica Acta" journal found CLA to prevent blood clot formation in arteries by the action of inhibiting arachiodonic acid and preventing platelet aggregation.
References
- "Applied Physiology, Nutrition and Metabolism"; A Meta-analysis of the Effects of Conjugated Linoleic Acid on Fat-free mass in humans; Dale Schoeller, et al.; 2009
- "American Journal of Clinical Nutrition"; Conjugated Linoleic Acid in Adipose Tissue and Risk of Myocardial Infarction; Liesbeth Smit, et al.; 2010
- "Biochemical and Biophysical Research Communications"Conjugated Linoleic Acid Prevents the Development of Essential Hypertension in Spontaneously Hypertensive Rats; Inoue, et al.; 2004
- "Biochimica and Biophysica Acta"; Antiplatelet Effects of Conjugated Linoleic Acid Isomers; Truitt, et al.;1999
- "Journal of Nutrition"; Arachidonic Acid in Adipose Tissue Is Associated with Nonfatal Acute Myocardial Infarction in the Central Valley of Costa Rica; Ana Baylin, et al.; 2004
