Garcinia Clinical Evidence

Garcinia Cambogia Extract

Journal of Medicine 

Preuss JG, et al. An overview of the safety and efficacy of a novel, natural(-)-hydroxycitric acid (HCA-SX) for weight management. 2004; 35(1-6):33-48. 

Topic: 
What is the effect of supplementation with SuperCitrimax (HCA-SX) on body weight and BMI?

Background:

HCA, derived from the peel of the Garcinia cambogia fruit, is a safe, effective tool for weight management. Previous laboratory research has demonstrated the safety and superior bioavailability of SuperCitrimax (HCA-SX), a novel calcium-potassium salt of HCA. Will it be effective in humans?

Study Type:

Human clinical trial

Study Design:

Placebo-controlled. Subjects took HCA-SX or a placebo. Researchers measured their body weight, BMI, cholesterol, leptin (a hormone that regulates appetite), serotonin (a neurotransmitter that reduces appetite), and fat metabolites excreted in urine at baseline, 4 weeks, and 8 weeks.

Subjects:

60 subjects

Dosage:

4,666.7 mg HCA-SX (2,800 mg HCA)/day in 3 equal doses for 8 weeks

Results:

Body weight and BMI decreased by 5.4% and 5.2%, respectively. Food intake, total cholesterol, LDL (bad cholesterol), triglyceride, and leptin levels all fell significantly while HDL (good cholesterol), serotonin, and excretion of fat metabolites (a marker of fat burning) rose significantly. There were no significant side effects.

Conclusion:

"These results demonstrate the safety, bioavailability and efficacy of HCA-SX in weight management." 

Physiology and Behavior 
Mattes RD, Bormann L. Effects of (-)-hydroxycitric acid on appetite variables. 2000 Oct 1-15; 71(1-2):87-94. 

Topic: 
Does HCA promote weight loss, and if so, how?

Background:

One theory of how HCA from Garcinia cambogia supports weight loss is that it suppresses hunger. Is this in fact how it works?

Study Type:

Human clinical study

Study Design:

Double-blind, placebo-controlled. Subjects took HCA or a placebo and researchers measured their body weight and appetitive variables at baseline and every 2 weeks for 12 weeks.

Subjects:

89 mildly overweight female subjects

Dosage:

2.4 g Garcinia cambogia (1.2 g HCA)/day (in 3 doses) for 12 weeks

Results:

Both groups lost weight, but the treatment group lost significantly more weight (3.7 +/- 3.1 kg vs. 2.4 +/- 2.9 kg). However, HCA did not affect appetite.

Conclusion:

"This study does not support a satiety effect of HCA." 

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International Journal of Obesity and Related Metabolic Disorders 
Thom E. Hydroxycitrate (HCA) in the treatment of obesity. 1996; 20(suppl 4):75. 

Topic: 
Is Citrimax a safe and effective supplement for weight loss?

Background:

Citrimax is a proprietary, branded form of HCA from Garcinia cambogia. Is itit effective for weight loss, and how does it affect blood pressure, cholesterol, and other health parameters?

Study Type:

Human clinical trial

Study Design:

Randomized, double-blind, placebo-controlled. Subjects took HCA or a placebo, consumed a 1,200 calorie/day diet, and were instructed to exercise 3 days a week. Researchers measured their body weight and other metabolic parameters.

Subjects:

60 obese subjects, 44 female and 16 male

Dosage:

1,320 mg/day for 8 weeks, divided into three doses 30 minutes before each meal

Results:

Subjects in the treatment group lost 6.4 kg, while subjects in the control group lost 3.8 kg, a highly significant difference. Moreover, more of the weight lost in the treatment group was fat (87%) than in the control group (80%). Blood pressure, cholesterol, and hip and waist circumference decreased in both groups but by significantly more in the treatment group. Appetite was significantly reduced in the treatment group but not in the control group.

Conclusion:

"HCA [Citrimax] is an effective and well tolerated short term treatment of overweight and obesity, when combined with a sensible low fat diet and exercise. Long term data are needed for efficacy and tolerability assessments." 

British Journal of Nutrition 
Oral hydroxycitrate supplementation enhances glycogen synthesis in exercised human skeletal muscle. 2012 Apr; 107(7): 1048-55. 

Topic: 
What is the effect of HCA supplementation on post-meal glycogen synthesis in exercised skeletal muscles?

Background:

The body uses glycogen stored in skeletal muscle as fuel for endurance exercise. Does HCA supplementation taken with a meal after endurance exercise increase glycogen synthesis?

Study Type:

Human clinical trial

Study Design:

Placebo-controlled, crossover trial. Subjects cycled for 60 minutes at 70-75% of their maximum aerobic capacity (VO2max) and then took HCA or a placebo with a high-carbohydrate meal. Muscle biopsies were taken. After a washout period of 7 days, the treatment and placebo groups switched places.

Subjects:

8 healthy male subjects (average age 22)

Dosage:

Single dose of 500 mg

Results:

HCA significantly lowered post-meal insulin response. Glycogen synthesis was 100% higher in the treatment group than in the placebo group. GLUT4 protein, an insulin-regulating protein, was significantly decreased in the treatment group, while fatty acid translocase (a protein that aids in the breakdown of fatty acids) was increased. Not surprisingly, fat oxidation (or the breakdown of fats) also significantly increased in those receiving HCA.

Conclusion:

"The present study reports the first evidence that HCA supplementation enhanced glycogen synthesis rate in exercised human skeletal muscle and improved post-meal insulin sensitivity." 

Mutation Research 
Downs BW, et al. Bioefficacy of a novel calcium-potassium salt of (-)-hydroxycitric acid. 2005 Nov 11; 579(1-2): 149-62. 

Topic: 
What are the benefits of supplementation with SuperCitrimax (HCA-SX)?

Background:

Most of the HCA in weight loss supplements binds to calcium, which results in poor solubility and bioavailablity. However, SuperCitrimax (HCA-SX) is water-soluble and thus more bioavailable. A dose of 4,500 mg/day is a good source of calcium and vitamin K, nutrients that play a key role in maintaining a healthy weight.

Study Type:

Review paper

Summary:

The authors found that HCA-SX:

  • Increases serotonin availability
  • Reduces appetite
  • Increases fat burning
  • Improves blood lipid levels
  • Reduces body weight
  • Modulates genes involved in obesity

Mechanism of Action:

HCA from Garcinia cambogia reduces fat synthesis and normalizes blood lipid profiles by competing with, and thus inhibiting, the enzyme ATP citrate lyase, which is important in the synthesis of fatty acids, cholesterol, and triglycerides. It also increases the burning of fatty acids, most likely by reducing malonyl-CoA, another enzyme that plays a role in the synthesis of fatty acids. HCA enhances the release and availability of serotonin, a neurotransmitter that reduces hunger. Finally, it increases synthesis of leptin, a hormone that signals satiety and reduces appetite. 

CHROMATE (CHROMIUM POLYNICOTINATE) 
10th International Congress of Toxicology (Finnish Society of Toxicology and the International Union of Toxicology)
Bagchi M, et al. Efficacy and toxicological assessment of a novel, niacin-bound chromium in ameliorating metabolic disorders. July 2004. Presented at the 10th International Congress of Toxicology-Finland. 

Topic: 
Can chromium lower blood sugar levels?

Background:

High blood sugar levels over time are a risk factor for developing diabetes. Chromium is a mineral known to play a role in helping insulin regulate blood sugar levels.

Study Type:

Human clinical intervention trial

Study Design:

Randomized, double-blind, placebo-controlled. Subjects took chromium or placebo. Researchers then measured their levels of HbA1c, a marker for blood sugar levels over a period of months.

Dosage:

300 mcg/day for 3 months

Subjects:

20 subjects

Results:

Subjects taking chromium had significantly lower fasting blood sugar levels, as determined by HbA1c, while the placebo group saw no change. 

Medicine and Science in Sports and Exercise 
Grant K, et al. Chromium and exercise training: effect on obese women. 1997 Aug;29(8):992-8. 

Topic: 
Can supplementation with chromium, with or without exercise, help obese women lose weight? What kind of chromium is the most effective?

Background:

Supplementation with chromium is thought to influence several risk factors for coronary artery disease (CAD) and non-insulin-dependent diabetes mellitus (NIDDM), such as body weight and blood sugar control.

Study Type:

Human clinical intervention trial

Study Design:

Subjects took chromium in one of two forms — chromium picolinate or chromium nicotinate. Their weight was tracked and their blood sugar was measured after an oral dose of glucose.

Dosage:

400 mcg/day

Subjects:

Young obese women

Results:

While supplementation with chromium picolinate actually caused significant weight gain, supplementation with chromium nicotinate, combined with exercise, caused significant weight loss and lowered insulin spikes after a dose of glucose, indicating better blood sugar control.

Conclusions

“Our results suggest that exercise training combined with chromium nicotinate supplementation may be more beneficial than exercise training alone for modification of certain CAD and NIDDM risk factors.”

Mechanism of Action:

Chromium is an essential mineral implicated in normal glucose and lipid homeostasis. There are several forms, but chromium polynicotinate is best absorbed due to the specific way it binds with niacin molecules, which may allow chromium to act on insulin receptors. Animal studies have shown that ChromeMate polynicotinate is 600% more bioavailable than chromium chloride and 300% more bioavailable than chromium picolinate. By helping to improve cellular uptake of glucose, ChromeMate reduces the amount of insulin needed to process sugar or carbohydrates from a meal. Reduced insulin levels help to prevent blood sugar from dropping too low, which would cause sugar cravings.

Chromium Safety Studies

Numerous animal and human studies, lasting anywhere from 90 days to 1 year, have been conducted on the safety of chromium. Chromium was found to be non-genotoxic (not damaging to DNA) and non-cytotoxic (not damaging to cells). A panel of experts from the Burdock Group, an independent toxicology group, concluded that chromium is safe for human consumption and generally recognized as safe (GRAS).