Conjugated Linoleic Acid Usage

While CLA is often recommended for aiding weight loss or improving body composition (ratio of muscle to fat), evidence from studies is conflicting. ¹ One meta-analysis (systematic statistical review) of all the data found minimal benefits at most. ² Another meta-analysis concluded that, when taken at a dose of 3.2 grams per day, CLA slightly reduces body fat levels. ³ Finally, in one study, a combination of CLA and chromium failed to improve body composition. ⁴

Note: Some, but not all studies have raised concerns that use of CLA by overweight people could raise insulin resistance and therefore increase risk of diabetes. In addition, it might increase cardiovascular risk in other ways, as described in the Safety Issues .

One study failed to find that CLA-enriched milk is helpful for metabolic syndrome , a condition associated with increased risk of heart disease. ⁵ A 12-week, double-blind, placebo-controlled study of 40 subjects tested CLA as a treatment for people with allergies to birch pollen (a common cause of hay fever ), and found some evidence of benefit. ⁶ A small double-blind trial found weak evidence that CLA might be useful for high cholesterol. ⁷ Some animal and test tube studies suggest that CLA might help prevent cancer , but the evidence is preliminary and inconsistent. ⁸ One study failed to find that CLA can enhance immune function. ⁹