Hydroxycitric acid (HCA), a derivative of citric acid, is found primarily in a small, sweet, purple fruit called the Malabar tamarind or, as it is most commonly called,
Garcinia cambogia. Test tube and animal research suggests that HCA may be helpful in weight loss because of its effects on metabolism. However, studies in humans have found mixed results.
HCA is not an essential nutrient. The Malabar tamarind is the only practical source of this supplement.
A typical dosage of HCA is 250 to 1,000 mg 3 times daily. Supplements are available in many forms, including tablets, capsules, powders, and even snack bars. Products are often labeled
and standardized to contain a fixed percentage of HCA.
Various proprietary forms of HCA are also available, often claimed by their promoters to be more effective.
test tube studies
as well as two human trials suggest that HCA might encourage
weight loss, other studies have found no benefit.1-14,20,21
It remains unclear whether HCA offers any weight-loss benefits.
In an 8-week
double-blind, placebo-controlled trial of 60 overweight individuals, use of HCA at a dose of 440 mg 3 times daily produced significant weight loss as compared to placebo.15
In contrast, a 12-week, double-blind, placebo-controlled trial of 135 overweight individuals, who were given either placebo or 500 mg of HCA (as
Garcinia cambogia extract standardized to contain 50% HCA) 3 times daily, found no effect on body weight or fat mass.16 However, this study has been criticized for using a high-fiber diet, which is thought to impair HCA absorption.17
A 12-week double-blind trial of 89 individuals found that HCA had no effect on appetite.18 Another study tested HCA to see if it could cause weight loss by altering metabolism, but no effects on metabolism were found.19
The Malabar tamarind (from which HCA is extracted) is a traditional food and flavoring in Southeast Asia. No serious side effects have been reported from animal or human studies involving either fruit extracts or the concentrated chemical. A proprietary calcium-potassium salt of HCA appears to have undergone considerable formal safety study, without evidence of toxicity appearing.20
However, maximum safe doses have not been established, especially for pregnant or nursing women, young children, or people with severe liver or kidney disease.
Greenwood MR, Cleary MP, Gruen R, et al. Effect of (-)-hydroxycitrate on development of obesity in the Zucker obese rat.
Am J Physiol. 1981;240:E72-E78.
Sullivan C, Triscari J. Metabolic regulation as a control for lipid disorders. I. Influence of hydroxycitrate on experimentally induced obesity in the rodent.
Am J Clin Nutr. 1977;30:767-776.
Sullivan AC, Triscari J, Hamilton JG, et al. Effect of (-)-hydroxycitrate upon the accumulation of lipid in the rat. I. Lipogenesis.
Sullivan AC, Triscari J, Hamilton JG, et al. Effect of (-)-hydroxycitrate upon the accumulation of lipid in the rat. II. Appetite.
Sergio W. A natural food, the malabar tamarind, may be effective in the treatment of obesity.
Medical Hypothesis. 1988;27:39-40.
Lowenstein JM. Effect of (-)-hydroxycitrate on fatty acid synthesis by rat liver in vivo.
J Biol Chem. 1971;246:629-632.
Triscari J, Sullivan AC. Comparative effects of (-)-hydroxycitrate and (+)-allo-hydroxycitrate on acetyl CoA carboxylase and fatty acid and cholesterol synthesis in vivo.
Cheema-Dhadli S, Halperin ML, Leznoff CC. Inhibition of enzymes which interact with citrate by (-)hydroxycitrate and 1,2,3,-tricarboxybenzene.
Eur J Biochem. 1973;38:98-102.
Sullivan AC, Hamilton JG, Miller ON, et al. Inhibition of lipogenesis in rat liver by (-)-hydroxycitrate.
Arch Biochem Biophys. 1972;150:183-190.
Heymsfield SB, Allison DB, Vasselli JR, et al. Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial.
Mattes RD, Bormann L. Effects of (-)-hydroxycitric acid on appetitive variables.
Physiol Behav. 2000;71:87-94.
Kriketos AD, Thompson HR, Greene H, et al. (-)-Hydroxycitric acid does not affect energy expenditure and substrate oxidation in adult males in a post-absorptive state.
Int J Obes Relat Metab Disord. 1999;23:867-873.
Thom E. Hydroxycitrate (HCA) in the treatment of obesity [abstract].
Int J Obes Relat Metab Disord.
Kovacs EM, Westerterp-Plantenga MS, Saris WH. The effects of 2-week ingestion of (-)-hydroxycitrate and (-)-hydroxycitrate combined with medium-chain triglycerides on satiety, fat oxidation, energy expenditure and body weight.
Int J Obes Relat Metab Disord.
Heymsfield SB, Allison DB, Vasselli JR, et al.
(hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial.
Badmaev V, Majeed M, Conte AA, et al.
for weight loss [letter].
Preuss HG, Rao CV, Garis R, et al. An overview of the safety and efficacy of a novel, natural(-)-hydroxycitric acid extract (HCA-SX) for weight management.
Vasques CA, Rossetto S, Halmenschlager G, et al. Evaluation of the pharmacotherapeutic efficacy of Garcinia cambogia plus Amorphophallus konjac for the treatment of obesity.
Last reviewed August 2013 by EBSCO CAM Review Board
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