(−)-Hydroxycitric acid is a specific isomer of hydroxycitric acid (HCA) derived from Garcinia cambogia and other Garcinia species. The fruit of these plants, often called assam fruit or assam gelugur, has been used for centuries as a culinary ingredient due to the distinct acidity imparted by the HCA and because it makes meals more filling and satisfying.
HCA has been touted for its positive effects on weight-loss and metabolism for some time. This is most often attributed to its action as an inhibitor of ATP citrate lyase, an enzyme necessary for the production of fat from sugar in the human body. There is extensive research detailing this activity, particularly as it was the prime motivation for a Roche drug development effort decades ago.
More recently additional biological effects have come to light beyond ATP citrate lyase inhibition. Now HCA is recognized as impacting inflammation, blood pressure, blood sugar, satiety, and overall cellular homeostasis. It is becoming clear that the strength of HCA as a dietary ingredient lies in its multiple modes of action (i.e. pleiotropic mechanisms).
As is true of many herbal products and their components, however, the benefits of HCA are dependent largely upon how it is prepared. In fact, HCA presents more challenges than most. For instance, is the HCA present in a form that is soluble in water, absorbable in the intestines, and bioavailable to tissues throughout the body? Careful processing of the ingredient, which can include removing obstructive constituents, is essential for HCA to work as promised. In fact, a critical analysis of HCA clinical trials illustrates that unsuccessful outcomes can typically be attributed to HCA that has been poorly prepared or given in inadequate quantities.
An increasing number of well-designed and appropriately controlled weight management studies in animals and humans have indicated that HCA is both safe and efficacious in weight management. Safety studies in experimental animals at up to 25 times the human equivalency doses did not produce hepatotoxicity or other significant adverse effects.
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