The new study, on a patent-pending form of HCA called SuperCitriMax, confirms the ingredient's efficacy and long-term safety, said the study's principal investigator, Dr Harry Preuss of Georgetown University Medical Center. It is also likely to help promote a number of new HCA-based products, being launched to fulfil demand for natural alternatives to ephedra.
HCA is extracted from a South Asian fruit called Garcinia cambogia, widely used for centuries in Asia as a flavoring agent and to make meals more 'filling'. It has also been used increasingly in supplements and previous ephedra supplier Metabolife International has added the extract to a new 'ephedra-free' range.
The new eight-week, randomized, double-blind study, published in January's issue of Nutrition Research (24(1): 45-58, 2004), found that Super CitriMax performed a function not noted in ephedra however - it significantly increased serum serotonin levels (a mechanism of appetite control and eating behavior) and lowered serum leptin levels, a biomarker of the gene that regulates obesity.
Super CitriMax is described as a high-dose, more bioavailable form of HCA and is bound to the minerals calcium and potassium.
In the pilot study, which was the initial phase of a larger 90 patient study, the researchers from Georgetown University Medical Center in Washington, D.C and Andhra University in India divided 30 human volunteers into three groups. Group A received Super CitriMax (2,800 mg HCA per day). Group B received a combination of Super CitriMax (2,800 mg HCA per day) plus niacin-bound chromium as ChromeMate (400 mcg chromium per day) and Gymnema sylvestre extract (400 mg providing 100 mg gymnemic acids per day). Group C received a placebo.
The supplements were administered daily before meals. All three groups were placed on a diet of 2,000 calories per day and participated in a 30-minute supervised walking program, five days a week.
After an eight-week period, those taking Super CitriMax alone experienced a decrease in body weight of over 12 pounds, or 6.2 per cent, and a 6.3 per cent reduction in BMI. Those taking Super CitriMax plus ChromeMate and Gymnema sylvestre experienced even greater losses, including a 15 pound (7.8 per cent) reduction in body weight and a 7.9 per cent reduction in BMI. In contrast, the placebo group experienced reductions of only 3 pounds or 1.6 per cent in body weight and a 1.7 per cent reduction in BMI.
Super CitriMax also demonstrated significant oxidation or 'burning' of fat, measured by urinary excretion of fat metabolites. This increased 25 - 158 per cent for Super CitriMax, said the reasearchers, but a combination of Super CitriMax plus ChromeMate and Gymnema sylvestre resulted in even greater excretion of fat metabolites, in the 46 - 181 per cent range. Subjects taking the placebo did not experience significant changes in urinary excretion fat metabolites.
Suprising researchers, serum serotonin levels, a mechanism of appetite control, increased by 40 per cent and 50 per cent in the Super CitriMax and combination groups, respectively, but only 21 per cent in the placebo group. Serum leptin levels, a biomarker of the obesity regulatory gene, decreased by 36.6 per cent for the Super CitriMax Group, 40.5 per cent for the combination group, and actually increased by 0.3 per cent in the placebo group.
"While we have believed for some time that HCA held significant promise in the treatment of obesity, this study, utilizing effective doses of bioavailable hydroxycitric acid, marks the first time that such a comprehensive, well-monitored clinical study has definitively confirmed its effectiveness in human subjects. Furthermore, its long-term safety opens the door to the possibility that the hydroxycitric acid available in Super CitriMax may be a valuable tool for long-term weight maintenance, one of the biggest challenges in the fight against obesity," said Dr Preuss.
Both the Super CitriMax and Super CitriMax-ChromeMate-Gymnema formulae are patent-pending. InterHealth says that its Super CitriMax is 100 per cent soluble compared to generic HCA products, which are typically less than 50 per cent soluble, and therefore less bioavailable to humans.
The company has introduced a new tradename and logo called Super CitriMax Full Strength, which will appear on the label of finished products that contain optimal dosages of Super CitriMax.
Other companies are also pushing the benefits of HCA. Rennaissance Herbs said this week it is to introduce new delivery methods and innovative uses for HCA under an exclusive licensing agreement with Glykon Technologies Group.
Glykon Technologies Group discovered and holds the rights to make claims regarding the impact of HCA on the regulation of insulin and blood sugar, modulation of leptin and glucocorticoids, improvements in bone mineralization, the regulation of immune function, and inflammation. The company also has patented multiple technologies greatly expanding the range of available delivery forms for HCA as well as improving its assimilation and activity.
The US market for diet pills came close to $900 million in sales in 2002 but will finish 2003 closer to $800 million, according to a new report from Kalorama Information.