May 20 2004
As Americans increasingly focus on healthy lifestyles, those concerned with maintaining their waistlines are once again faced with the task of shrinking that winter bulge. A study to be published in the June issue of The American Journal of Clinical Nutrition concludes that the dietary supplement, conjugated linoleic acid (CLA), reduces body fat mass in overweight, but otherwise healthy, adults by as much as nine percent.
The randomized, double blind, placebo-controlled study is the first to document the long-term safety and efficacy of CLA supplementation over a 12- month period without additional lifestyle or dietary restrictions.
This clinical trial is an ensuing study to previous animal and human trials that found CLA improves body composition by reducing fat and preserving lean muscle tissue. CLA has been clinically proven to aid in the maintenance of lean tissue and may help tone the body without necessarily causing overall weight loss.
It is thought to do this by decreasing the amount of fat stored after eating, increasing the rate of fat breakdown and metabolism -- helping the body use its existing fat for energy -- and decreasing the total number of fat cells.
"The results of this first long-term study indicate that CLA, taken for one year as a dietary supplement, safely improves the ratio of body fat to lean tissue in overweight, but otherwise healthy, adults," said Dr. Jean- Michel Gaullier, of Scandinavian Clinical Research in Kjeller, Norway, and project manager of the study. "Study participants who took 3.4 grams of CLA per day experienced a significant reduction in their body fat mass compared to those in the placebo group.
These results confirm a trend observed in previous short-term CLA studies." One hundred and eighty healthy men and women volunteers, ages 18 to 65, with a body mass index (BMI) of 25-30 kg/m2 (indicating that they were overweight) were randomized to receive gel capsules containing either 3.4 grams CLA-free fatty acid, 3.4 grams CLA-triglycerides or equivalent amounts of olive oil (placebo).
Patients were then followed for 12 months. Weight, BMI, vital signs and adverse events were recorded every three months. Body composition and blood samples were analyzed at regular intervals throughout the study, and participants were monitored continuously for any signs of serious adverse events.
At baseline, there was no difference between the groups for either weight, BMI, body fat mass or lean body mass. After only six months of observation, individuals taking either form of CLA experienced a significant reduction in body fat mass, while those in the placebo group saw no change. Daily caloric intake and exercise was not different between groups either at zero or 12 months and thus most likely did not play a role in body composition changes observed in the CLA groups.
Both forms of CLA were equally efficacious in body fat mass reduction and proven safe, when used for one year in healthy, yet overweight, adults. Study related adverse events, typically rated as "mild" or "moderate" in nature, were nearly equal among groups taking either CLA or placebo (3-5 percent). The most common side effect was gastrointestinal complaints.
The CLA used in this study was TONALIN(R) CLA, an exclusive product of the Cognis Group. TONALIN(R), the number one consumer brand of CLA, is intended to help consumers lose body fat, maintain lean body mass, prevent fat regain and contribute to improved overall health. TONALIN(R) CLA is available as a dietary supplement sold in health food stores, retail chains and pharmacies. According to the American Obesity Association, nearly 70 million U.S. adults are obese or severely obese.
These individuals are at increased risk of illness from hypertension, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, respiratory problems and certain cancers. Interest in CLA has been spurred by consumers' increased demand for safe, non- stimulant products for reducing unwanted inches.
CLA's apparent metabolic and chemoprotective properties in animals, as well as some similar, initial results in humans, also gained attention in the past. Some of the effects seen in animals include reduced body fat content, improved serum lipid profiles, decreased aortic lipid deposition and improved glucose control that delays the onset of diabetes.