A pilot study investigating the effect of Caralluma fimbriata extract on the risk factors of metabolic syndrome in overweight and obese subjects: a randomised controlled clinical trial (original) (raw)
Summary
Objectives
Design
This was a randomised, double blind placebo controlled clinical trial. Forty-three adults aged 29-59 years were recruited. The eligibility criteria included a Body Mass Index (BMI) >25
kg/m2, or a waist circumference >94
cm (male), >80
cm (female). Thirty-three participants completed the 12-week study at Victoria University Nutritional Therapy Clinic. Participants were randomly assigned into two groups. C. fimbriata extract and placebo were orally administered as 500
mg capsules twice daily (1
g/day) and dietary intake and exercise were monitored weekly.
Results
The results of thirty-three participants (experimental group, n
=
17; placebo group n
=
- were analysed. The primary outcome measure was the decline in waist circumference. By week 9, the experimental group had lost 5.7
cm, compared to only 2.8
cm loss in the placebo group (Difference: −2.890; 95% CI; −5.802 to 0.023). Post intervention, the experimental group had lost 6.5
cm compared to 2.6
cm loss in the placebo group (Difference: −3.847; 95% CI; −7.466 to 0.228). Waist to hip ratio (WHR) also improved significantly after 12 weeks intervention in the experimental group, with a total reduction of 0.03 being recorded compared to 0.01 increase in the placebo group (Difference: −0.033; 95% CI; −0.064 to −0.002). There was also a significant decline in the palatability (visual appeal, smell, taste) of the test meal and sodium intake in the experimental group at week 12 (p
<
0.05). In addition a significant reduction in body weight, BMI, hip circumference, systolic BP, HR, triglyceride levels, total fat and saturated fat intake within both groups was observed following the intervention period (p
<
0.05).
Conclusion
Supplementation with C. fimbriata extract whilst controlling overall dietary intake and physical activity may potentially play a role in curbing central obesity, the key component of metabolic syndrome. Controlling dietary intake and exercise improved body weight and favourably influenced the metabolic risk profile.
Introduction
Metabolic syndrome is a complex disorder characterised by a clustering of cardiovascular risk factors including abdominal/central obesity, dyslipidemia, elevated plasma glucose levels and elevated BP.1 Central obesity is one of the major determinants of metabolic syndrome.2 Pathological mechanisms involved in metabolic syndrome include ectopic lipid accumulation resulting in lipotoxicity and altered secretion of adipocytokines (adipocyte-derived hormones).2 Visceral fat is metabolically active as a source of adipocytokines chiefly leptin,3 adiponectin,4 plasminogen activator inhibitor type 1,5 tumour necrosis factor alpha6 and non-esterified fatty acids.7
The majority of individuals affected by metabolic syndrome are overweight or obese, thus dietary treatment is focused on weight reduction.8 Strategies for body fat reduction typically involve a combination of lifestyle changes such as limiting calorie intake, increasing physical activity, behavioural therapy, pharmacotherapy, and surgery.9 The availability and popularity of natural dietary supplements for weight loss has risen dramatically in recent years.
Among potential natural supplements for weight reduction are the appetite suppressants. One such supplement is the extract of Caralluma fimbriata, an edible succulent plant, in the Asclepiadaceae family, native to India.10 Indian tribal people have used the natural appetite suppressant for many centuries, and in times of famine it is a commonly used vegetable.10 The appetite suppressing properties of C. fimbriata has been attributed to the active component, pregnane glycosides.11 The mechanism of appetite suppression by pregnane glycosides is unclear, however one hypothesis is that C. fimbriata may down-regulate ghrelin synthesis in the stomach and neuropeptide-Y in the hypothalamus, resulting in appetite suppression.12
Preliminary human clinical trials have shown significant weight reductions in overweight Indian subjects with supplementation of C. fimbriata extract in addition to lifestyle modification.13 A study by Kuriyan et al.9 on the appetite suppressing effects of C. fimbriata in overweight Indian adults (25-60 yrs) showed a significant reduction in waist circumference after two months intervention. In addition the hunger level of participants reduced by 20% which may account for an 8% decline in energy intake of the experimental group.10 However, Kuriyan et al. 9 did not identify a significant reduction in blood lipid profile in the subjects with or without C. fimbriata supplementation. Also, no human trials have reported the effect of C. fimbriata extract on other metabolic risk factors including plasma glucose levels, BP and adipocytokines such as leptin. The aim of this study was to determine whether C. fimbriata extract, in addition to a hypocalorie diet (deficit of 500
kcal/day of estimated energy requirements) and regular physical activity, can attenuate metabolic disturbances including central obesity, elevated BP, dyslipidemia and elevated blood glucose levels in generally healthy and obese Australian adults.
Section snippets
Participants
This study was a randomised, double blind, placebo controlled clinical trial. It was conducted at Victoria University, Nutritional Therapy Clinic, Melbourne, Australia. Potential volunteers were recruited through the general public and staff members at Victoria University. The recruitment period was approximately four months. Thirty-three volunteers (29-59 years), with a BMI greater than 25
kg/m2 or a waist circumference >94
cm (male), >80
cm (female) were randomly assigned (Fig. 1) into either
Results
All screened volunteers met the inclusion criteria (n
=
43). Ten participants (five in the experimental and five in the placebo group) did not complete the trial due to work and family commitments. These participants were excluded from the study (Fig. 1). In addition, there was no breach of the blinding process identified throughout the intervention period.
The physical characteristics of the participants including age, body weight, BMI, waist and hip circumference and WHR were not significantly
Discussion
The present study demonstrated that supplementation with C. fimbriata extract in combination with a hypocalorie diet was associated with a clinically significant reduction in central adiposity, a major component of metabolic syndrome. The primary finding was a decline in waist circumference following 12 weeks supplementation in the experimental group. The observed treatment effect (treatment minus placebo) is markedly stronger in this study compared to that reported in the study by Kuriyan et
Conclusion
The present study suggests that supplementation with C. fimbriata extract was associated with a clinically meaningful reduction in central adiposity. The controlled exercise recommendations and modifications to dietary intake were linked with favourable changes of metabolic risk factors and an improvement in general health and wellbeing in overweight and obese Australian adults. This study may hold therapeutic promise as an approach for the treatment of obesity and associated lifestyle related
Acknowledgements
We wish to thank the study participants for their cooperation and effort. The raw C. fimbriata powder used in this study was provided by Gencor Pacific Group, Hong Kong. Both C. fimbriata and placebo capsules were formulated by AZPA Pty Ltd, Melbourne, Australia. We thank the late Mrs Dawn Bannon for her help with blood collection. We also like to thank Dr Crispin Dass for his assistance with the FLUO star/POLAR Galaxy microplate reader. We wish to thank Dr Ewa Sztendur and Dr Mark Scarr for
Cited by (32)
2018, Disease-a-Month
A number of “medicinal” plants are being studied which have shown anti-obesity effects in addition to Garcinia cambogia. These plants include Camellia sinensis, Caralluma fimbriata, Cissus quadrangularis, Curcuma longa, Emblica officinalis, Nigella sativa, Portulaca oleracea L, Salacia oblonga, Panax ginseng (ginseng), Zingiber officinale (zingiber), Momordica charantia (bitter mellon) and others.437,438,462,472,473 Hoodia is part of the family Apocynaceae, a southern African plant (stapeliads), and Hoodia gordonii is the best known of a number of Hoodia species.474–476
View all citing articles on Scopus
Copyright © 2013 Elsevier Ltd. All rights reserved.