Conjugated linoleic acid, or CLA, refers to a group of polyunsaturated fatty acids found in dairy products and beef. CLA is an essential fatty acid which means it has to come from the diet since the body does not make it. Its primary role in the body is for brain function, growth, development and cell structure. The reasons people take CLA as a supplement are for its purported health benefits in cancer prevention, weight control and high cholesterol, explains the Memorial Sloan-Kettering Cancer Center.
Lowering Cholesterol
A function of CLA is in reducing high cholesterol levels. Several studies show the positive effect CLA has on cholesterol. A study in the 2004 "American Journal of Clinical Nutrition" led by researcher Sabine Tricon provided a CLA supplement to healthy men for eight weeks and assessed the effect on cholesterol levels. The cis-9 trans-11 form of CLA lowers LDL cholesterol and total cholesterol in this study. It is important to note from this study that one isomer is better for cholesterol than the other. The CLA isomer trans-10 cis-12 form actually raises cholesterol levels.
Preventing Cancer
CLA also has a function cancer prevention. There are couple of ways in which CLA is able to provide these effects. A study in the 2002 "Journal of Nutrition" led by researcher Martha A. Belury discussed that CLA is able to prevent cancer by inhibiting the process by which a cell turns into a cancerous cell, regulates cell division and growth and regulates cell death. It is important to note this study was done on mice rather than humans. Another study in the 2006 "Anti Cancer Research" journal led by researcher Li-Shu Wang studied the effect of CLA on human breast cancer cells and found CLA is able to cause tumor suppressor genes to work better. More research needs to be completed in this area, but does show promise.
Weight Control
CLA has a function in weight control. Several studies have shown promise, but a study in the 2007 "International Journal of Obesity" led by researcher A.C. Watras, shows a practical and realistic benefit of CLA. Forty healthy overweight participants were given 3.2g of CLA per day for six months. Results indicate CLA supplements are able to reduce fat mass and prevent weight gain during the holiday season. As with other topics, more research needs to be completed to make strong health claims. Always discuss taking a supplement with a physician.
References
- Memorial Sloan-Kettering Cancer Center: Conjugated Linoleic Acid
- "American Journal of Clinical Nutrition"; Opposing Effects of cis-9,trans-11 and Trans-10,cis-12 Conjugated Linoleic Acid on Blood Lipids in Healthy Humans; Sabine Tricon, et al.; Sept. 2004
- "Journal of Nutrition"; Inhibition of Carcinogenesis by Conjugated Linoleic Acid: Potential Mechanisms of Action; Martha A. Belury; Oct. 2002
- "Anti Cancer Research"; Conjugated Linoleic Acid (CLA) Up-regulates the Estrogenregulated Cancer Suppressor Gene, Protein Tyrosine Phosphatase Á (PTPÁ), in Human Breast Cell; Li-Shu Wang, et al.; Jan./Feb. 2006
- "International Journal of Obesity"; The Role of Conjugated Linoleic Acid in Reducing Body Fat and Preventing Holiday Weight Gain; A.C. Watras, et al.; Mar. 2007
Member Comments