BACKGROUND: Cell and animal studies, as well as short-term clinical trials, have demonstrated that CLA, a naturally occurring fat in beef and dairy products, may have many potential health benefits. These benefits have included a reduction in body fat stores while maintaining lean muscle, enhancement of the immune system, and a lower risk of cancer.
RESEARCH: Researchers asked 180 healthy, overweight men and women, ages 18 to 65, to take one of three supplements daily for 12 months. One supplement was a CLA-free fatty acid supplement (providing 3.6 grams of CLA daily). The second was a CLA-triglyceride supplement (providing 3.4 grams of CLA). The third supplement was a placebo containing an equivalent amount of olive oil. Participants took the supplements without lifestyle or dietary restrictions.
RESULTS: After 6 months, as well as after 12 months, subjects taking either of the two CLA supplements experienced a significant reduction in body fat mass, while those taking placebos had no change. The supplements were generally well tolerated. Side effects associated with supplementation were primarily gastrointestinal and the incidence did not differ significantly among the three groups.
IMPLICATIONS: The researchers concluded that CLA supplements "administered either in the triglyceride or free fatty acid form to healthy overweight adults for one year results in a significant decrease of body fat mass." This is the first long-term study to demonstrate that CLA supplements can help people reduce body fat mass while maintaining lean muscle.
Gaullier JM, Halse J, Hoye K, et al. Conjugated linoleic acid supplementation for one year reduces body fat mass in healthy, overweight humans. American Journal of Clinical Nutrition, 2004;79:1118-1125.
For the original scientific abstract, visit: