Obesity afflicts one-third of the U.S. population, with nearly 45% of overweight and 67% of obese individuals trying to lose weight.1,2 With the beginning of the new year, even more people are likely making resolutions to lose weight.
Weight is a key modifiable risk factor for preventable causes of death due to heart disease, stroke, and type 2 diabetes.1 Even a modest weight loss of 5% to 10% over 6 months may be beneficial.3 Many dietary supplements claim to promote easy weight loss. One supplement, Garcinia cambogia, claims to have beneficial weight reduction and lipid-lowering effects.
G. cambogia and HCA
The active ingredient in G. cambogia, hydroxycitric acid (HCA), is a competitive inhibitor of adenosine triphosphate citrate lyase, a key enzyme in the synthesis of fatty acids, cholesterol, and triglycerides. HCA is thought to improve the body’s ability to break down fat, increase satiety, and increase high-density lipoprotein cholesterol. These effects may improve exercise tolerance, decrease fat storage, and improve lipids.4
Many G. cambogia products exist, with each containing different HCA concentrations. For weight loss, an extract containing 50% HCA, 1,000 mg three times daily or 500 mg four times daily, has been used. A mild adverse effect profile has been established, including headache, nausea, upper respiratory tract symptoms, and gastrointestinal symptoms.4 In 2009, FDA warned patients about the risk of liver toxicity with the dietary supplement Hydroxycut, which contained G. cambogia at the time. However, FDA was unable to determine if G. cambogia was the true cause of the events or if they were attributable to other ingredients.5
Key clinical trial
A recent randomized, double-blind study of 43 obese women aged 25 to 60 years evaluated the efficacy of G. cambogia compared with placebo.6 Key exclusion criteria were pregnancy/lactation, type 2 diabetes, bariatric surgery, untreated hypertension, smoking cessation within the past 6 months, and use of medications affecting weight.
Participants received 800 mg (50% HCA) of G. cambogia capsules three times daily or matched placebo 30 minutes before meals. Anthropometric variables such as body mass index (BMI) and free fat mass were measured, among many others. Lipid and lipoprotein values were also evaluated before and after 60 days. All patients followed a dietary plan and were instructed to maintain physical activity throughout the study.
Results showed no statistical differences between groups except with respect to triglycerides (TG). A significant decrease in TG was observed in the G. cambogia group (−22.9 ± 5.3) compared with an increase in the placebo group (+4.53 ± 33.4). However, patients treated with G. cambogia experienced a slight increase in BMI, while patients receiving placebo had a slight decrease in BMI (+0.17 kg/m2 and −0.24 kg/m2, respectively). Liver enzymes and creatinine clearance were unchanged. Gastric discomfort occurred in three patients receiving G. cambogia, compared with one patient in the placebo group. This was a small study with a short duration similar to other studies of supplements, and its results do not provide additional clarity for G. cambogia’s use in weight loss and lipids.
What to tell patients
Obesity is associated with an increased risk of cardiovascular disease (CVD) mortality. Although G. cambogia has received media attention for control of weight and cholesterol, the evidence of its benefits remains limited. Patients with CVD risk factors should be encouraged to manage their hypertension, diabetes, and dyslipidemia. A dietary intake of 1,200 to 1,500 kcal/d for women and 1,500 to 1,800 kcal/d for men, along with physical activity, should be encouraged to achieve 5% to 10% of weight loss within 6 months.
References
- www.cdc.gov/obesity/data/adult.html
- https://ods.od.nih.gov/factsheets/WeightLoss-HealthProfessional/#en3
- Obesity. 2014;22(S2):S1–S410
- www.naturaldatabase.com
- www.fda.gov/downloads/ForConsumers/ConsumerUpdates/UCM152222.pdf
- Phytother. 2014;28:887–91