Literature Briefs-Analysis by Cydney E. McQueen, PharmD
Garcinia cambogia for Weight Loss
Source: Heymsfield SB, et al. Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: A randomized controlled trial. JAMA 1998;280:1596-1600.
Objective: To examine effectiveness of Garcinia cambogia (50% hydroxycitric acid, a citrate cleavage enzyme inhibitor) extract for weight loss and fat mass reduction.
Design and Setting: A RDBCT conducted at the Obesity Research Center at St. Luke’s-Roosevelt Hospital, Columbia University, New York, NY.
Subjects: One hundred thirty-five subjects (M=19, F=116) with a body mass index of 27-38 kg/m2, who had not dieted with weight loss in the past six months.
Treatment: A high-fiber, 1,200 Kcal/d diet plus either G. cambogia extract or placebo.
Dose/Duration: 3,000 mg/d G. cambogia extract in three divided doses 30 minutes before meals for 12 weeks.
Outcome Measures: Body weight change and change in fat mass measured by pencil-beam dual-energy x-ray absorptiometry (DXA) scanner.
Results: There was no significant difference in mean weight loss between treatment and placebo groups (4.1 kg vs. 3.2 kg, respectively, P = 0.14). Mean percentage of fat mass loss for each group (2.16% in the placebo group vs. 1.44% in the treatment group, P = 0.21) also did not differ significantly when tested with analysis of covariance for age, sex, and pretest percentage of fat mass. Several secondary analyses were performed and the authors stated that all findings were consistent with the primary analysis.
Strengths/Limitations: This well-designed trial had very thorough statistical analyses and met power. The treatment dose was at the extreme low end of a previously determined dose-response curve. Treatment and placebo groups had a significant difference after randomization in regard to total body fat mass of men (2.6% vs. 5.9%, respectively). Because of various mechanical problems, several patients’ DXA readings were estimated on the basis of other measurements. In addition, medication compliance was monitored, however, dietary compliance was not.
Level of Evidence: Level I, several major limitations.
Comments: Subjects were asked to "maintain a stable physical activity level" throughout the trial, but no information was provided about exercise or activity levels of the groups. Although the investigators did adequately address problems found in earlier studies, other procedural concerns are evident. Lack of monitoring of dietary compliance gives rise to the possibility of great differences between the groups and is a serious limitation, as is the low dose used.
Clinical Impact: At this time, G. cambogia extract is not recommended as an aid to weight loss due to lack of documented efficacy. A larger, rigorously designed trial using a higher dose needs to be performed to either confirm lack of efficacy or characterize any possible benefit.