Thursday, August 13, 2009
What is it? Hydroxycitric Acid (HCA) is derived from the fruit of the Garcinia cambogia plant, a plant found in South Asia. HCA is marketed as being able to block the conversion of excess carbohydrate calories into stored bodyfat. HCA blocks an enzyme called ATP#Citrate Lyase.
This enzyme is involved in the early production of fat synthesis. By blocking this enzyme, it's believe more carbohydrate calories will be stored as glycogen in muscle tissue and the liver while less excess calories from carbohydrates will be stored as body fat.
The basic metabolic rule is, when the body tops off its stores of glycogen (stored muscle sugars) any excess carbohydrates will be burned off as heat (i.e. thermic effects) and stored as bodyfat. ATP#Citrate lyase is a key enzyme in that system. HCA is marketed to a lesser degree as an appetite suppressant. It may also enhance thermogenesis, which is the production of heat from food and may be beneficial in reducing total cholesterol and LDL ("bad" cholesterol) levels.
What does the research have to say?
In vitro (test tube) research has shown HCA to block ATP#citrate lyase. In animals, HCA appears to be a legitimate weight loss agent. Several decades of
animal research has shown HCA to be a good appetite suppressant, presumably by sending the fullness (satiety) signal to the brain after changes in glycogen status in the liver. Rats and mice given HCA eat less food and gain less bodyfat from the food they ingest.
The real issue here is that there has been little contemporary human research or data regarding the effects of HCA on weight loss with several studies finding no effects in people. As we all know, the metabolism of rats and humans are quite different so the positive animal studies may not be duplicated or possible in humans.
What does the real world have to say?
HCA is a product that has been around for quite a while. The vast majority of feedback regarding weight loss with people using HCA has been negative in my experience. At higher doses, some people do feel HCA has a mild anorectic (appetite suppressing) effect.