Context. Hydroxycitric acid (HCA), the active ingredient in the herbal compound Garcinia Cambogia, competitively inhibits the extramitochondrial enzyme adenosine triphosphate–citrate (pro-3S)-lyase. As a citrate cleavage enzyme that may play an essential role in de novo lipogenesis inhibition, G cambogia is claimed to lower body weight and reduce fat mass in humans.
To evaluate the efficacy of Garcinia Cambogia for body weight and fat mass loss in overweight human subjects.
Twelve-week randomized, double-blind, placebo-controlled trial.
Outpatient weight control research unit.
Overweight men and women subjects (mean body mass index [weight in kilograms divided by the square of height in meters], approximately 32 kg/m2).
Subjects were randomized to receive either active herbal compound (1500 mg of hydroxycitric acid per day) or placebo, and both groups were prescribed a high-fiber, low-energy diet. The treatment period was 12 weeks. Body weight was evaluated every other week and fat mass was measured at weeks 0 and 12.
Main Outcome Measures
Body weight change and fat mass change.
A total of 135 subjects were randomized to either active hydroxycitric acid (n=66) or placebo (n=69); 42 (64%) in the active hydroxycitric acid group and 42 (61%) in the placebo group completed 12 weeks of treatment (P=.74). Patients in both groups lost a significant amount of weight during the 12-week treatment period (P<.001); however, between-group weight loss differences were not statistically significant (mean [SD], 3.2 [3.3] kg vs 4.1 [3.9] kg; P=.14). There were no significant differences in estimated percentage of body fat mass loss between treatment groups, and the fraction of subject weight loss as fat was not influenced by treatment group.
Garcinia cambogia failed to produce significant weight loss and fat mass loss beyond that observed with placebo.
EXCESSIVE ADIPOSITY and its concomitant health risks are among the most common conditions managed by health care practitioners. The limited long-term effectiveness of conventional weight management, including behavioral therapy, is the impetus of major efforts aimed at developing alternative pharmacologic and surgical weight reduction treatment strategies. A rapidly growing therapeutic area, and one widely embraced by the general public, is the use of herbal weight loss products.
An herb-derived compound, hydroxycitric acid, is now incorporated into many commercial weight loss products. Obtained from extracts of related plants native to India, mainly Garcinia cambogia and Garcinia indica , hydroxycitric acid was first identified by Watson and Lowenstein in the late 1960s as a potent competitive inhibitor of the extramitochondrial enzyme adenosine triphosphate–citrate (pro-3 S)-lyase. These investigators and others subsequently demonstrated both in vitro and in vivo that hydroxycitric acid in animals not only inhibited the actions of citrate cleavage enzyme and suppressed de novo fatty acid synthesis, but also increased rates of hepatic glycogen synthesis, suppressed food intake, and decreased body weight gain.
Although hydroxycitric acid appears to be a promising experimental weight control agent, studies in humans are limited and results have been contradictory (also R. Ramos, J. Flores Saenz, F. Alarcon, unpublished data, 1996, and G. Kaats, D. Pullin, L. Parker, S. Keith, unpublished data, 1996). Supporting evidence of human hydroxycitric acid efficacy for weight control is based largely on studies with small sample sizes, studies that failed to include a placebo-treated group, and use of inaccurate measures of body lipid change. Although hydroxycitric acid effectiveness remains unclear, at least 14 separate hydroxycitric acid–containing products are presently sold over-the-counter to consumers. This investigation was designed to overcome limitations of earlier studies and examine the effectiveness of hydroxycitric acid for weight loss and fat mass reduction in a rigorous controlled trial.
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JAMA - The Journal of the American Medical Association (1998;280(18):1596-1600)