Weight Loss Supplements
Over the counter weight loss supplements are not regulated by the FDA and are not classified as drugs. Because they are not classified as drugs there is no regulation on their distribution or the manufacturing process. And there usually are no stringently performed research studies that evaluate the efficacy and side effects of most weight loss supplements. Although the way to lose weight is simple, the execution is difficult. Many people turn to weight loss supplements because changing their eating habits is difficult for them and using supplements and pills can sometimes help reduce the challenge. Others also want fast progress and fast weight loss.
Weight loss supplements fall into two large categories; over the counter and prescription medications. Prescription supplements are only available by a physician and a licensed pharmacist. Prescription medications have undergone severe testing by the Federal Food and Drug Administration (FDA). The manufacturing of these products is also regulated. Over the counter weight loss supplements are not regulated by the FDA and are not classified as drugs. Because they are not classified as drugs there is no regulation on their distribution or the manufacturing process. There usually are no stringently performed research studies that evaluate the efficacy and side effects of the weight loss supplements.
Hydroxycitric acid (HCA) and Garcinia cambogia:
Hydroxycitric acid (HCA), derived from the Garcinia cambogia fruit, is safe, and may be an effective tool for weight management. Super Citrimax (HCA-SX), a novel calcium-potassium salt of HCA, has been shown by prior laboratory studies to be safe and absorbed well by the body. In a clinical study, subjects (n=60) took 4,666.7 mg/day HCA-SX (containing 2,800 mg HCA) in 3 equal doses or a placebo for 8 weeks. Participants were also put on a 2,000 kcal diet/day and a 30 min walking exercise program 5 days/week. At the end of the study, a 5.4% and 5.2%, reduction in weight and body mass index, respectively, was reported. Food consumption, total cholesterol, LDL ‘bad’ cholesterol, triglyceride, and leptin levels (regulate appetite and metabolism) were significantly reduced. Additionally, HDL ‘good’ cholesterol, serotonin, and markers indicating fat burning increased significantly. No side-effects were reported. (1)
A 2-week laboratory study of fat cells from obese women found that low dose HCA-SX, a weight loss product containing hydroxycitric acid (HCA, derived from the Garcinia cambogia fruit) may induce lipolysis or the breakdown of fats/lipids. Additionally, HCA-SX had a positive effect on leptin, a molecule responsible for appetite regulation and metabolism. (2)
Mattes RD reported in a double-blind placebo controlled randomized trial that Garcinia cambogia (2.4 g/d, containing 1.2 g/day hydroxycitric acid) administered to overweight women (restricted to a 5020 kJ diet) had no effect on food intake or appetite suppression in a 12-week study. However, women taking G. cambogia (n=42) or placebo (n=47) both reported weight loss, though those taking G. cambogia had significantly greater weight loss (3.7 kg vs 2.4 kg). The study supports that weight loss did not occur by appetite suppression. (3)
The results of animal studies and double blind, placebo controlled human clinical studies, reveal that hydroxycitric acid (HCA) not only reduces weight, but also is safe. No treatment-related side-effects were reported in these studies. Furthermore, the authors conclude that HCA at a dose of up to 2800 mg/d is safe for human consumption. (4)
A laboratory evaluation of rats supplemented with 0, 0.2, 2.0 and 5.0% HCA-SX (Hydroxycitric acid Super CitriMax, derived from the Garcinia cambogia fruit), a popular supplement for weight loss, revealed that HCA-SX reduced body weight without affecting major organs, blood results, or tissue diagnosis of disease. (5)
Hydroxycitric acid (HCA), derived from the Garcinia cambogia fruit and often used to achieve weight loss, failed to provide significant weight reduction or fat mass loss in a group of overweight individuals. For 12-weeks, in addition to following a high-fiber/low-energy diet, participants were administered either 1500 mg/day of HCA (n=66) or placebo (n=69). At the end of the study, participants in both groups lost a significant amount of weight (average loss: -3.2 kg vs -4.1 kg). However, there was no significant difference between the groups for either weight or fat reduction, indicating that HCA had no additional benefit when compared to placebo. (6)
Summary: Hydroxycitric acid (HCA)
Hydroxycitric acid (HCA), derived from the Garcinia cambogia fruit in a dose up to 2,800 mg of HCA divided in 3 equal doses per day taken for weight loss has been described as safe without side effects in 2 reviews focused on safety of the agent. However, results from the research reviewed has shown mixed results. 1 review and 1 double-blind randomized placebo controlled clinical trial found HCA did not differ significantly compared to a diet and exercise program alone. This result provided more credibility to diet and exercise than the HCA. 1 randomized placebo controlled clinical trial by Mattes RD reported a greater weight loss of 3.7 kg vs 2.4 kg with 1200 mg of HCA per day vs. placebo in obese patients but weight loss did not occur by appetite suppression, a hypothesis promoted by other research as the mechanism for action. The remaining research reviewed was less credible for supporting HCA for use in weight loss. More research is needed on HCA.
References:
1.Preuss HG, Rao CV, Garis R, et al. An overview of the safety and efficacy of a novel, natural(-)-hydroxycitric acid extract (HCA-SX) for weight management. J Med. 2004;35:33-48. http://www.ncbi.nlm.nih.gov/pubmed/18084863
2.Roy S, Shah H, Rink C, et al. Transcriptome of primary adipocytes from obese women in response to a novel hydroxycitric acid-based dietary supplement. DNA Cell Biol. 2007 Sep;26(9):627-39. http://www.ncbi.nlm.nih.gov/pubmed/17708719
3.Mattes RD, Bormann L. Effects of (-)-hydroxycitric acid on appetitive variables. Physiol Behav. 2000 Oct1-15;71(1-2):87-94. http://www.ncbi.nlm.nih.gov/pubmed/11134690
4.Soni MG, Burdock GA, Preuss HG, et al. Safety assessment of (-)-hydroxycitric acid and Super CitriMax®, a novel calcium/potassium salt. Food and Chemical Toxicology 2004 Sep; 42(9):1513-1529. http://www.ncbi.nlm.nih.gov/pubmed/15234082
5.Shara M, Ohia SE, Schmidt RE, et al. Physico-chemical properties of a novel (-)-hydroxycitric acid extract and its effect on body weight, selected organ weights, hepatic lipid peroxidation and DNA fragmentation, hematology and clinical chemistry, and histopathological changes over a period of 90 days. Mol Cell Biochem 2004; 260: 171-186. http://www.ncbi.nlm.nih.gov/pubmed/15228099
6.Heymsfield SB, Allison DB, Vasselli JR, et al. Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial. JAMA. 1998 Nov 11;280(18):1596-1600. http://www.ncbi.nlm.nih.gov/pubmed/9820262