Garcinia cambogia is yet another entrant in the growing list of natural supplements being marketed as the answer to obesity. G. cambogia is most well-known for its use as a spice. This product, which is classified as a fruit, is naturally found throughout southeastern Asia, India and western Africa.1

One of nearly 300 species of Garcinia, G. cambogia is the one most studied for its weight-loss potential.1G. cambogia grows as a small tree and produces a rusty-red round fruit.2 It is the rind of this fruit that is used for both culinary and therapeutic purposes.2


Background


Obesity is a tremendous health problem, not just in the United States but globally as well. An estimated 1 billion adults worldwide are overweight, and nearly one-third of those are considered clinically obese.3 In the United States alone, the overall cost of obesity was estimated by the CDC to be nearly $150 billion per year.4

G. cambogia became popular as a weight-loss aid when it was noted to enhance satiety in its native regions.5 A secondary effect of the fruit is its potent laxative action.6 The active ingredient of G. cambogia is hydroxycitric acid (HCA).5 




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Science


The mechanism of fat metabolism is complex, and the role of G. cambogia in this process is debatable. Metabolically, HCA appears to be the source of early satiety. This acid enters the energy-production process of the Kreb’s cycle and ultimately increases hepatic glycogen synthesis and inhibits formation of low-density lipoproteins.5

This is thought to signal to our brains that we have had enough to eat. Some suggest that HCA interacts with the production of the adipose-controlling hormone leptin, but these claims have yet to be substantiated by clinical trials.


In a meta-analysis literature review, researchers identified only 23 trials that met review criteria.7 Fewer than half of those ultimately met the proper standards for well-done randomized, placebo-controlled trials. After the final data analysis, use of G. cambogia was associated with a very slight (0.88 kg) weight loss over control groups, but also with twice the number of adverse GI effects. 


Korean researchers studied the effects of G. cambogia, placebo, and another weight-loss supplement in 86 overweight adults in a 10-week randomized trial.8 At the end of the study, no statistically significant weight loss was found in any of the three groups. 


In another small trial, researchers studied 24 overweight adults over two weeks of daily intake of G. cambogia HCA extract.5 In addition to actual weight loss being monitored, 24-hour energy intake was tracked. By the end of the trial, energy intake was reduced by 15% to 30% in the 
G. cambogia group over placebo, with a very modest trend in weight loss. 


Finally, a study in India focused on 60 obese individuals who were randomized to HCA plus two other supplements, or placebo.9 At the end of eight weeks, both HCA groups had a 5% to 6% reduction in weight and BMI. Food intake, total cholesterol, LDL cholesterol, and triglycerides all decreased in the HCA groups, and HDL levels increased. 



Safety


Unfortunately, evidence-based literature demonstrates the potential for adverse events in G. cambogia/HCA. In addition to significant GI upset, increasing reports of hepatic injury are surfacing. For example, researchers found that daily feeding with HCA supplement did result in decreased fat accumulation and glucose resistance in obese mice, but at the expense of significant hepatic fibrotic changes and inflammation.1

Several cases of acute liver failure and another resulting in death have been associated with a popular weight-loss product composed primarily of HCA.10,11 As a result, the FDA publicly warned health-care providers about the possible association of this product with lethal liver damage, and the product was removed from the marketplace.12

Interactions cost, how supplied


Drug or herbal interactions with G. cambogia are speculative; however, caution should be used when combining this agent with any product that is metabolized primarily through the liver. A month’s supply of dried powder-filled capsules costs about $30, depending on the source.



Summary


The identification of a simple, safe, affordable weight-loss product would be a welcome in our society. However, the threat of potentially life-threatening liver disease is a stong deterrent to G. cambogia use. Regardless of the current data, it is clear that more human clinical trials need to be conducted before health-care providers can give informed support for this product. 


References


  1. Kim YJ, Choi MS, Park YB, et al. Garcinia Cambogia 
attenuates diet-induced adiposity but exacerbates hepatic collagen accumulation and inflammation. World J Gastroenterol. 2013;19:4689-4701. Available at www.ncbi.nlm.nih.gov/pmc/articles/PMC3732841/.

  2. Márquez F, Babio N, Bulló M, Salas-Salvadó J. Evaluation of the safety and efficacy of hydroxycitric acid or Garcinia cambogia extracts in humans. Crit Rev Food Sci Nutr. 2012;52:585-594. 

  3. Shrivastava, D. Formulation of sustained release tablet of anti-obesity drug Garcinia cambogia. World Journal of Pharmacy and Pharmaceutical Sciences. 2012;1: 731-743.

  4. Centers for Disease Control and Prevention. Adult obesity facts. Available at www.cdc.gov/obesity/data/adult.html.

  5. Westerterp-Plantenga MS, Kovacs EM. The effect of (-)-hydroxycitrate on energy intake and satiety in overweight humans. Int J Obes Relat Metab Disord. 2002;26:870-872.

  6. Skidmore-Roth, L. Mosby’s Handbook of Herbs & Natural Supplements. 3rd ed. Elsevier Mosby; St. Louis: 2006:23-35

  7. Onakpoya I, Hung SK, Perry R, et al. The use of Garcinia extract (hydroxycitric acid) as a weight loss supplement: A systematic review and meta-analysis of randomized clinical trials. J Obes. 2011;2011:509038. Available at www.ncbi.nlm.nih.gov/pmc/articles/PMC3010674.

  8. Kim JE, Jeon SM, Park KH, et al. Does Glycine max leaves 
or Garcinia Cambogia promote weight-loss or lower plasma cholesterol in overweight individuals: a randomized control trial. Nutr J. 2011;10:94. Available at www.ncbi.nlm.nih.gov/pmc/articles/PMC3189865.

  9. Preuss HG, Bagchi D, Bagchi M, et al. Effects of a natural extract of (-)-hydroxycitric acid (HCA-SX) and a combination of 
HCA-SX plus niacin-bound chromium and Gymnema sylvestre extract on weight loss. Diabetes Obes Metab. 2004;6:171-180.

  10. Stevens T, Qadri A, Zein NN. Two patients with acute liver injury associated with use of the herbal weight-loss 
supplement Hydroxycut. Ann Intern Med. 2005;142:477-478.

  11. McDonnell WM, Bhattacharya R, Halldorson JB. Fulminant hepatic failure after use of the herbal weight-loss supplement Exilis. Ann Intern Med. 2009;151:673-674.

  12. Ezine. Hydroxycitric acid, bad science and liver failure. Available at ezinearticles.com/?Hydroxycitric-Acid,-Bad
-Science-and-Liver-Failure&id=2342676.



All electronic documents accessed December 3, 2013.