Life Extension Magazine October 2010
Effect of glucomannan on obese patients: a clinical study.
An eight-week double-blind trial was conducted to test purified glucomannan fiber as a food supplement in 20 obese subjects. Glucomannan fiber (from konjac root) or placebo was given in 1-g doses (two 500 mg capsules) with 8 oz water, 1 h prior to each of three meals per d. Subjects were instructed not to change their eating or exercise patterns. Results showed a significant mean weight loss (5.5 lbs) using glucomannan over an eight-week period. Serum cholesterol and low-density lipoprotein cholesterol were significantly reduced (21.7 and 15.0 mg/dL respectively) in the glucomannan treated group. No adverse reactions to glucomannan were reported.
Int J Obes. 1984;8(4):289-93
IGOB131, a novel seed extract of the West African plant Irvingia gabonensis, significantly reduces body weight and improves metabolic parameters in overweight humans in a randomized double-blind placebo controlled investigation.
BACKGROUND: A recent in vitro study indicates that IGOB131, a novel seed extract of the traditional West African food plant Irvingia gabonensis, favorably impacts adipogenesis through a variety of critical metabolic pathways including PPAR gamma, leptin, adiponectin, and glycerol-3 phosphate dehydrogenase. This study was therefore aimed at evaluating the effects of IGOB131, an extract of Irvingia gabonensis, on body weight and associated metabolic parameters in overweight human volunteers. METHODS: The study participants comprised of 102 healthy, overweight and/or obese volunteers (defined as BMI > 25 kg/m2) randomly divided into two groups. The groups received on a daily basis, either 150 mg of IGOB131 or matching placebo in a double blinded fashion, 30-60 minutes before lunch and dinner. At baseline, 4, 8, and 10 weeks of the study, subjects were evaluated for changes in anthropometrics and metabolic parameters to include fasting lipids, blood glucose, C-reactive protein, adiponectin, and leptin. RESULTS: Significant improvements in body weight, body fat, and waist circumference as well as plasma total cholesterol, LDL cholesterol, blood glucose, C-reactive protein, adiponectin and leptin levels were observed in the IGOB131 group compared with the placebo group. CONCLUSION: Irvingia gabonensis administered 150 mg twice daily before meals to overweight and/or obese human volunteers favorably impacts body weight and a variety of parameters characteristic of the metabolic syndrome. This is the first double blind randomized placebo controlled clinical trial regarding the anti-obesity and lipid profile modulating effects of an Irvingia gabonensis extract. The positive clinical results, together with our previously published mechanisms of gene expression modulation related to key metabolic pathways in lipid metabolism, provide impetus for much larger clinical studies. Irvingia gabonensis extract may prove to be a useful tool in dealing with the emerging global epidemics of obesity, hyperlipidemia, insulin resistance, and their co-morbid conditions.
Lipids Health Dis. 2009 Mar 2;8:7
Chronic use of glucomannan in the dietary treatment of severe obesity.
Two groups of 25 severely obese patients underwent 3 months of hypocaloric diet therapy either alone or associated with a glucomannan-based fibrous diet supplement (approx. 4 g/die in 3 doses). The comparative analysis of the results obtained in both groups showed that the diet + glucomannan group had a more significant weight loss in relation to the fatty mass alone, an overall improvement in lipid status and carbohydrate tolerance, and a greater adherence to the diet in the absence of any relevant side effects. Due to the marked ability to satiate patients and the positive metabolic effects, glucomannan diet supplements have been found to be particularly efficacious and well tolerated even in the long-term treatment of severe obesity.
Minerva Med. 1992 Mar;83(3):135-9
Traditional uses and potential health benefits of Amorphophallus konjac K. Koch ex N.E.Br.
Amorphophallus konjac (konjac) has long been used in China, Japan and South East Asia as a food source and as a traditional medicine. Flour extracted from the corm of this species is used in Far Eastern cuisine to make noodles, tofu and snacks. In traditional Chinese medicine (TCM), a gel prepared from the flour has been used for detoxification, tumour-suppression, blood stasis alleviation and phlegm liquefaction; and for more than 2,000 years has been consumed by the indigenous people of China for the treatment of asthma, cough, hernia, breast pain, burns as well as haematological and skin disorders. Over the past two decades, purified konjac flour, commonly known as konjac glucomannan (KGM) has been introduced on a relatively small scale into the United States and Europe, both as a food additive and a dietary supplement. The latter is available in capsule form or as a drink mix and in food products. Clinical studies have demonstrated that supplementing the diet with KGM significantly lowers plasma cholesterol, improves carbohydrate metabolism, bowel movement and colonic ecology. Standards for the classification of both konjac flour and KGM have been established by the Chinese Ministry of Agriculture, the European Commission and the US Food Chemicals Codex. However, to date, there is no worldwide agreed regulatory standard for konjac flour or KGM. This highlights the need for harmonization of konjac commercial standards to assess and ensure the quality of existing and future KGM products. Despite the widespread consumption of konjac derived products in East and South East Asia, there has been limited research on the biology, processing and cultivation of this species in the West. Most studies performed outside Asia have focussed on the structural characterisation and physicochemical properties of KGM. Therefore, the objective of this monograph is to review the literature covering the ethnic uses, botany and cultivation of konjac corms, together with the health benefits of KGM with the associated requirements for quality control. Possible directions for future research and development and standardisation of production and classification of this versatile natural product will be discussed.
J Ethnopharmacol. 2010 Mar 24;128(2):268-78
Blocking carbohydrate absorption and weight loss: a clinical trial using Phase 2 brand proprietary fractionated white bean extract.
BACKGROUND: Phase 2’ starch neutralizer brand bean extract product (“Phase 2”) is a water-extract of a common white bean (Phaseolus vulgaris) that has been shown in vitro to inhibit the digestive enzyme alpha-amylase. Inhibiting this enzyme may prevent the digestion of complex carbohydrates, thus decreasing the number of carbohydrate calories absorbed and potentially promoting weight loss. METHODS: Fifty obese adults were screened to participate in a randomized, double-blind, placebo-controlled study evaluating the effects of treatment with Phase 2 versus placebo on weight loss. Participants were randomized to receive either 1,500 mg Phase 2 or an identical placebo twice daily with meals. The active study period was eight weeks. Thirty-nine subjects completed the initial screening process and 27 subjects completed the study. RESULTS: The results after eight weeks demonstrated the Phase 2 group lost an average of 3.79 lbs (average of 0.47 lb per week) compared with the placebo group, which lost an average of 1.65 lbs (average of 0.21 lb per week), representing a difference of 129% (p=0.35). Triglyceride levels in the Phase 2 group were reduced an average of 26.3 mg/dL, more than three times greater a reduction than observed in the placebo group (8.2 mg/dL) (p=0.07). No adverse events during the study were attributed to the study medication. CONCLUSION: Clinical trends were identified for weight loss and a decrease in triglycerides, although statistical significance was not reached. Phase 2 shows potential promise as an adjunct therapy in the treatment of obesity and hypertriglyceridemia and further studies with larger numbers of subjects are warranted to conclusively demonstrate effectiveness.
Altern Med Rev. 2004 Mar;9(1):63-9
A Dietary supplement containing standardized Phaseolus vulgaris extract influences body composition of overweight men and women.
BACKGROUND: More than one billion human adults worldwide are overweight and, therefore, are at higher risk of developing cardiovascular diseases, diabetes, and a variety of other chronic perturbations. Many believe that use of natural dietary supplements could aid in the struggle against obesity. So-called “starch blockers” are listed among natural weight loss supplements. Theoretically, they may promote weight loss by interfering with the breakdown of complex carbohydrates thereby reducing, or at least slowing, the digestive availability of carbohydrate-derived calories and/or by providing resistant starches to the lower gastrointestinal tract. AIMS: The present research study examines a dietary supplement containing 445 mg of Phaseolus vulgaris extract derived from the white kidney bean, previously shown to inhibit the activity of the digestive enzyme alpha amylase, on body composition of overweight human subjects. METHODS: A randomized, double-blinded, placebo-controlled study was conducted on 60 pre-selected, slightly overweight volunteers, whose weight had been essentially stable for at least six months. The volunteers were divided into two groups, homogeneous for age, gender, and body weight. The test product containing Phaseolus vulgaris extract and the placebo were taken one tablet per day for 30 consecutive days before a main meal rich in carbohydrates. Each subject’s body weight, fat and non-fat mass, skin fold thickness, and waist/hip/thigh circumferences were measured. RESULTS: After 30 days, subjects receiving Phaseolus vulgaris extract with a carbohydrate-rich, 2,000- to 2,200-calorie diet had significantly (p<0.001) greater reduction of body weight, BMI, fat mass, adipose tissue thickness, and waist,/hip/ thigh circumferences while maintaining lean body mass compared to subjects receiving placebo. CONCLUSION: The results indicate that Phaseolus vulgaris extract produces significant decrements in body weight and suggest decrements in fat mass in the face of maintained lean body mass.
Int J Med Sci. 2007 Jan 24;4(1):45-52
Fat storage in adipocytes requires inactivation of leptin’s paracrine activity: implications for treatment of human obesity.
Hyperleptinemia rapidly depletes adipocyte fat in lean rats, whereas comparable hyperleptinemia produced by adipocytes in diet-induced obesity does not, implying a leptinergic blockade in adipocytes during overnutrition. Indeed, activated STAT-3 in white adipose tissue (WAT) of normal rats was less on a 60% high fat diet (HFD) than on 4% fat, despite a 10-fold higher plasma leptin. In 6 days of a HFD, mRNA of the postreceptor leptin inhibitor, suppressor of cytokine signaling-3, increased 22-fold in WAT, while leptin receptor (Lepr-b) mRNA gradually disappeared, implying leptinergic blockade at both postreceptor and receptor levels. Adipocyte-specific Lepr-b overexpression of a Lepr-b transgene completely prevented the adipocyte hypertrophy and hyperplasia and the increase in body fat induced in wild-type mice by HFD. Activated STAT-3 and AMP-activated protein kinase (AMPK), and the mRNA of lipooxidative enzymes, peroxisome proliferator-activated receptor-gamma-coactivator-1alpha, and uncoupling protein-1 and -2 were increased in WAT. Body temperature was elevated in the transgenic mice, suggesting uncoupled fatty acid oxidation of surplus fatty acids. In conclusion, storage of surplus calories in WAT and the development of diet-induced obesity require the blockade of a latent leptin-stimulated caloric sump in white adipocytes.
Proc Natl Acad Sci U S A. 2005 Dec 13;102(50):18011-6
Weight-reducing effects of the plasma protein encoded by the obese gene.
The gene product of the ob locus is important in the regulation of body weight. The ob product was shown to be present as a 16-kilodalton protein in mouse and human plasma but was undetectable in plasma from C57BL/6J ob/ob mice. Plasma levels of this protein were increased in diabetic (db) mice, a mutant thought to be resistant to the effects of ob. Daily intraperitoneal injections of either mouse or human recombinant OB protein reduced the body weight of ob/ob mice by 30% after 2 weeks of treatment with no apparent toxicity but had no effect on db/db mice. The protein reduced food intake and increased energy expenditure in ob/ob mice. Injections of wild-type mice twice daily with the mouse protein resulted in a sustained 12% weight loss, decreased food intake, and a reduction of body fat from 12.2 to 0.7%. These data suggest that the OB protein serves an endocrine function to regulate body fat stores.
Science. 1995 Jul 28;269(5223):543-6
Digestive and hepatic enzymes in streptozotocin-induced diabetic rats fed supplements of dikanut (Irvingia gabonensis) and cellulose.
In a feeding trial involving dikanut (an African viscous fibre) and cellulose (a particulate fibre), diabetic rats were maintained for 4 weeks on each of the test fibres. The levels of digestive and membrane-bound enzymes of the intestine, and hepatic glycolytic enzymes were determined. The effect of the supplements on intestinal morphology was also assessed. The two types of dietary fibre caused a general reduction in the levels of all the intestinal enzymes assayed with the effect of dikanut supplementation resulting in more drastic reductions. Evidence was obtained for a marked alteration in the intestinal morphology. It was concluded that the reduced absorption of glucose resulted in its lowered level in the blood and urine. The disruption of the mucosal membrane may also curtail the absorption of glucose. On the other hand, the activities of hepatic glycolytic enzymes became elevated to efficiently utilize the low substrates reaching the liver. The dietary fibres caused a shift away from the depletion of glycogen by the diabetic rat to synthesis of the storage polysaccharide. The long-term effects of the several adaptive responses resulting in lowered blood glucose from feeding these dietary fibre supplements to the diabetic rat requires further research.
Ann Nutr Metab. 1993;37(1):14-23
Inhibition of Irvingia gabonensis seed extract (OB131) on adipogenesis as mediated via down regulation of the PPARgamma and leptin genes and up-regulation of the adiponectin gene.
BACKGROUND: Endeavors to manage obesity have been heavily reliant on controlling energy intake and expenditure equilibrium, but have failed to curtail the overweight and obesity epidemic. This dynamic equilibrium is more complex than originally postulated and is influenced by lifestyle, calorie and nutrient intake, reward cravings and satiation, energy metabolism, stress response capabilities, immune metabolism and genetics. Fat metabolism is an important indicator of how efficiently and to what extent these factors are competently integrating. We investigated whether an Irvingia gabonensis seed extract (IGOB131) would provide a more beneficial comprehensive approach influencing multiple mechanisms and specifically PPAR gamma, leptin and adiponectin gene expressions, important in anti-obesity strategies. METHODS: Using murine 3T3-L1 adipocytes as a model for adipose cell biology research, the effects of IGOB131 were investigated on PPAR gamma, adiponectin, and leptin. These adipocytes were harvested 8 days after the initiation of differentiation and treated with 0 to 250 microM of IGOB131 for 12 and 24 h at 37 degree C in a humidified 5 percent CO2 incubator. The relative expression of PPAR gamma, adiponectin, and leptin in 3T3-L1 adipocytes was quantified densitometrically using the software LabWorks 4.5, and calculated according to the reference bands of beta-actin. RESULTS: The IGOB131 significantly inhibited adipogenesis in adipocytes. The effect appears to be mediated through the down-regulated expression of adipogenic transcription factors (PPAR gamma) [P less than 0.05] and adipocyte-specific proteins (leptin) [P less than 0.05], and by up-regulated expression of adiponectin [P less than 0.05]. CONCLUSION: IGOB131 may play an important multifaceted role in the control of adipogenesis and have further implications in in-vivo anti obesity effects by targeting the PPAR gamma gene, a known contributory factor to obesity in humans.
Lipids Health Dis. 2008 Nov 13;7:44
Coupling Vascular and Myocardial Inflammatory Injury into a Common Phenotype of Cardiovascular Dysfunction: Systemic Inflammation and Aging - A Mini-Review.
The rising epidemic of cardiovascular (CV) disease is fuelled by obesity, hypertension and diabetes and, independently and cumulatively, by an aging population. Extensive research identified immunoinflammatory mechanisms as key drivers in the initiation and progression of the disease, from early asymptomatic stages of vascular and myocardial injury leading to the clinically manifest dysfunction and remodeling in advanced stages. Underlying processes include endothelial dysfunction and extracellular matrix restructuration leading to increased vascular stiffness, as well as myocardial remodeling with dilatation and wall thinning. In this, overproduction of tumor necrosis factor-alpha, amongst others, contributes to generalized CV injury and dysfunction. Moreover, recent insights into the involvement of innate and adaptive immunity in atherosclerosis have shed light on many interesting parallels with chronic systemic inflammatory conditions, such as rheumatoid arthritis, with aggravated inflammation-induced vascular and myocardial injury. Besides, chronologic age has been identified as a potent, independent risk for reduced CV capacity and a plethora of heart diseases, with other modifiable risk factors acting as accelerators. We discuss the available evidence and propose that characterization of inflammatory CV responses might reveal a distinctive CV inflammatory phenotype. A comprehensive noninvasive bio-signature, comprising immunomic biomarkers and integrated noninvasive imaging, may serve as a potential tool in the early diagnosis and prognostication of CV risk.
Gerontology. 2010 Jun 11