May 22, 2006 -- Researchers continue to probe whether or not supplements of conjugated linoleic acid (CLA) affect weight loss.
A new study shows that obese or overweight people who took CLA supplements every day for six months lost about 3 extra pounds than those who took a daily pill containing only olive oil, which doesn't include CLA (placebo).
That study, presented in Los Angeles, at Digestive Disease Week 2006, was funded by Lipid Nutrition, a company that makes CLA weight loss products. Lipid Nutrition's Sandra Einerhand, PhD, was the chief researcher.
Another recent study came to a different conclusion. In March, researchers reported in the American Journal of Clinical Nutrition that obese people who took CLA supplements for a year didn't lose more weight than those who took a placebo.
Latest CLA Study
Einerhand's study included 118 people who were overweight or obese, based on BMI (body mass index). A total of 105 participants finished the study, Einerhand told reporters in a teleconference.
Participants' BMI (body mass index) ranged from 28 to 32. BMI relates weight to height. BMI of 30 or more is considered obese; BMI of 25 to 29.9 is considered overweight but not obese.
Einerhand and colleagues randomly assigned participants to take either the CLA or placebo capsules daily for six months. Participants didn't know if they'd gotten CLA or the placebo.
Three months into the study, the CLA group had lost an extra 1.5 pounds of body fat, compared to the placebo group, the study shows.
At the study's end, the CLA group lost 5.6% more body fat mass than those taking the placebo. The CLA group also lost about 3.3 pounds more than the placebo group.
Where the Fat Was Lost
Women in the CLA group lost fat from their legs and abdomen. Men in the CLA group lost fat from their abdomens. CLA wasn't associated with fat loss from the arms, Einerhand told reporters.
No adverse events were related to CLA and participants' sensitivity to insulin -- a hormone that controls blood sugar -- didn't change during the study, Einerhand also said.
"This study shows that CLA supplementation for six months in healthy overweight and obese adults affected body fat mass in specific regions of the body and was well tolerated," write Einerhand and colleagues in their study's abstract.
"All effects were independent of diet and exercise," Einerhand told reporters, adding that waist size and waist-to-hip ratio also dropped in the CLA group (waist size dropped by about 1.2 inches).
As for BMI, "individuals with the highest BMI responded best to CLA," the researchers write.
Einerhand's study and the other study published in March's issue of the American Journal of Clinical Nutrition both used the same CLA dose. The studies had similar numbers of participants. The study in the American Journal of Clinical Nutrition only included moderately obese people and lasted for a year, twice as long as Einerhand's study. The study in the American Journal of Clinical Nutrition was funded by another company that makes CLA products, Cognis Corporation.