Altern Ther Health Med. 2007 Jul-Aug;13(4):32-7.
University of California, Los Angeles School of Medicine, USA.
A proprietary fractionated white bean extract of Phaseolus vulgaris has been shown in vitro to inhibit the digestive enzyme alpha-amylase. This may prevent or delay the digestion of complex carbohydrates, potentially resulting in weight loss.
A 4-week randomized, double-blind, placebo-controlled study of 25 healthy subjects consuming 1000 mg of a proprietary fractioned white bean extract or an identical placebo twice a day before meals in conjunction with a multi-component weight-loss program, including diet, exercise, and behavioral intervention, was conducted.
Both groups reduced their weight and waist size significantly from baseline. The active group lost 6.0 lbs (P=.0002) and 2.2 in (P=.0050), and the placebo group lost 4.7 lbs (P=.0016) and 2.1 in (P=.0001). The differences between groups were not significant (weight P=.4235, waist size P=.8654). Through subsequent exploratory analysis to investigate group findings further, subjects were stratified by total dietary carbohydrate intake. This probative analysis revealed that the tertile of subjects who had consumed the most carbohydrates demonstrated significant reductions in both weight (8.7 lbs vs 1.7 lbs, P=.0412) and waist size (3.3 in vs 1.3 in P=.0100) compared with placebo subjects in the same tertile of carbohydrate intake.
Subjects who adhere to a program including dietary modification, exercise, and behavioral intervention can significantly reduce their weight and waist size in a short period of time. In an exploratory analysis of data, the tertile of subjects who ate the most carbohydrates experienced a significant reduction in both weight and waist size with the addition of the white bean extract compared to the placebo group of the same tertile of carbohydrate consumption. Longer studies with a larger pool of subjects are required to validate these findings.
Nutr J. 2011 Mar 17;10:24. doi: 10.1186/1475-2891-10-24.
Medicus Research LLC, Northridge, CA 91325, USA.
Obesity, and resultant health hazards which include diabetes, cardiovascular disease and metabolic syndrome, are worldwide medical problems. Control of diet and exercise are cornerstones of the management of excess weight. Foods with a low glycemic index may reduce the risk of diabetes and heart disease as well as their complications. As an alternative to a low glycemic index diet, there is a growing body of research into products that slow the absorption of carbohydrates through the inhibition of enzymes responsible for their digestion. These products include alpha-amylase and glucosidase inhibitors. The common white bean (Phaseolus vulgaris) produces an alpha-amylase inhibitor, which has been characterized and tested in numerous clinical studies. A specific and proprietary product named Phase 2® Carb Controller (Pharmachem Laboratories, Kearny, NJ) has demonstrated the ability to cause weight loss with doses of 500 to 3000 mg per day, in either a single dose or in divided doses. Clinical studies also show that Phase 2 has the ability to reduce the post-prandial spike in blood glucose levels. Experiments conducted incorporating Phase 2 into food and beverage products have found that it can be integrated into various products without losing activity or altering the appearance, texture or taste of the food. There have been no serious side effects reported following consumption of Phase 2. Gastro-intestinal side effects are rare and diminish upon extended use of the product. In summary, Phase 2 has the potential to induce weight loss and reduce spikes in blood sugar caused by carbohydrates through its alpha-amylase inhibiting activity.
J Am Diet Assoc. 2009 May;109(5):909-13. doi: 10.1016/j.jada.2009.02.029.
Diet Assessment Center, Department of Nutritional Sciences, Pennsylvania State University, 108 Chandlee, University Park, PA 16802, USA. firstname.lastname@example.org
The US Department of Agriculture’s MyPyramid guidelines introduced a near doubling of the dietary recommendations for vegetables. These recommendations target specific subgroups of vegetables, including dry beans and peas. Dry beans and peas provide an array of nutrients and phytochemicals that have been shown to have beneficial health effects, yet consumption levels in the United States are quite low. Few studies have examined the influence of legume consumption on nutrient intakes. Therefore, the purpose of this study was to assess nutrient and food group intakes of dry bean and pea consumers compared to nonconsumers. Dietary intake data from the 1999-2002 National Health and Nutrition Examination Survey for adults aged > or =19 years was used. Results show that on any given day only 7.9% of adults are consuming dry beans and peas; Mexican Americans or other Hispanics are more likely to be consumers than nonconsumers. Consuming approximately (1/2) c dry beans or peas resulted in higher intakes of fiber, protein, folate, zinc, iron, and magnesium with lower intakes of saturated fat and total fat. These data support the specific recommendation for dry beans and peas as part of the overall vegetable recommendation. Increased consumption of dry beans and peas-economical and nutrient-rich foods-could improve the diet quality of Americans.
Plant Foods Hum Nutr. 1995 Dec;48(4):349-65.
Département de Science et Technologie des Aliments, Université Laval, Ste-Foy, Qc Canada.
A common bean variety, grown in Burundi, was either fermented, soaked and/or cooked, and then assessed for nutrient composition, in-vitro starch digestibility and protein nutritive value. A decrease in ash, most minerals, vitamins, and some essential amino acids was noted for soaked, cooked and soaked-cooked beans. Compared to untreated beans, soaking decreased soluble sugar (9.8 percent) but increased starch (7.3 percent) and soluble fiber (16.9 percent). In cooked beans, an increase in soluble sugar (1.5 percent), and a decrease in thiamine (81.7 percent), starch (24.6 percent) and soluble fiber (16.6 percent) and nitrogen (2.9 percent) contents were observed. Crude fiber (6.9 percent) and starch (10.0 percent) increased while fat (17.6 percent), fatty acids (linoleic: 10.7 percent; linolenic: 14.3 percent) and soluble sugars (25.4 percent) and nitrogen (14.4 percent) decreased in soaked-cooked beans. Fermentation increased potassium (11.6 percent), soluble fiber (18.9 percent), and some amino acids but decreased fatty acids (linoleic: 13.5 percent; linolenic: 19.9 percent), soluble sugar (75.2 percent) and vitamin (riboflavin: 41.0 percent; niacin: 24.5 percent) contents in common beans. However, the in-vitro starch digestibility was greatly improved (12.3 percent) by cooking while it decreased in soaked beans (29.2 percent). Soaking-cooking and fermentation did not have any significant effect on the digestibility of common bean starch. Finally, among the five treatments applied to common beans, only fermentation showed a significant improvement (8.3 percent) on the protein nutritive value of this legume.
J Nutr Sci Vitaminol (Tokyo). 2002 Aug;48(4):283-9.
Departamento de Planejamento Alimentar e Nutrição, Faculdade de Engenharia de Alimentos, Universidade Estadual de Campinas, Caixa Postal 6121, 13083-970, Campinas, SP, Brasil.
The objective of this study was to verify the effect of soaking on the factors causing flatulence in the common bean (Phaseolus vulgaris, L.) cv. IAC-Carioca during domestic preparation. A biological assay using recently weaned (21 days) male Wistar rats provided the Food Conversion Efficiency (FCE) and the Net Protein Ratio (NPR). Five treatments were carried out with isocaloric (350.9 +/- 37.9 kcal/100 g) and isoprotein (12.0 +/- 0.5%) experimental diets, with the following protein sources: beans cooked without soaking (BNS), beans soaked and cooked with the soaking water (BSWW), beans soaked and cooked without the residual soaking water (BSNW), control diet (casein) (CC), casein plus the total soluble solids found in the soaking water (CSS) for comparative purposes, and an aproteic diet (AP) for corrective purposes, all diets offered ad libitum. The contents of raffinose-type oligosaccharides were determined in the different domestic preparations of the beans. Significant reductions were observed in the contents of the oligosaccharides raffinose (25.0%), stachyose (24.8%), and verbascose (41.7%), and in the contents of total sugars (80.6%), reducing sugars (58.2%), nonreducing sugars (90.3%), and starch (26.8%) when soaking took place before cooking and elimination of the soaking water not absorbed by the beans (BSNW) was used. No significant difference (p > 0.05) was observed between the values for FCE and NPR of the control diet (casein) and control diet plus soaking water soluble solids. Neither was any significant difference between the values for the different bean treatments found, though the values for FCE and NPR were lower than those obtained for casein treatments. Thus it was verified that although the domestic preparation of the common bean significantly reduced the contents of raffinose-type oligosaccharides, total reducing and nonreducing sugars and starch, it did not interfere with its nutritive value.
J Am Coll Nutr. 2009 Jun;28(3):266-76.
Georgetown University Medical Center, Departments of Physiology, Medicine and Pathology, 4000 Reservoir Road, NW, Washington, D.C. 20057, USA. email@example.com
Many believe that excessive intake of refined carbohydrates (CHO) plays a major role in the development of obesity/overweight, type 2 diabetes mellitus and insulin resistance, a collection of events commonly referred to as “diabesity,” and have sought natural means to overcome these linked perturbations. As a first approach, planned diets with low portions of refined CHO have become popular. However, these diets do not satisfy everyone; and many are concerned over replacing CHO with more fats. As a second option, addition of soluble fiber to the diet can slow absorption of refined CHO, i.e., lower the glycemic index of foods and overcome or at least ameliorate many of the adverse reactions resulting from increased refined CHO ingestion. Unfortunately, the general public does not favor diets high in fiber content, and various fibers can lead to gastrointestinal problems such as gas and diarrhea. A third choice to favorably influence CHO absorption is to use natural dietary supplements that block or slow CHO absorption in the gastrointestinal tract via inhibiting enzymes necessary for CHO absorption -amylase and alpha-glucosidases. Although a number of natural supplements with anti-amylase activity have been recognized, the most studied and favored one is white kidney bean extract. Animal and human studies clearly show that this agent works in vivo and has clinical utility. This paper reviews many aspects of diabesity and the use of “carb blockers” to prevent and ameliorate the situation. In many respects, carb blockers mimic the beneficial effects of fibers.
Int J Med Sci. 2007 Aug 6;4(4):196-202.
Georgetown University Medical Center, Department of Physiology, Washington, DC 20057, USA.
Rapid gastrointestinal absorption of refined carbohydrates (CHO) is linked to perturbed glucose-insulin metabolism that is, in turn, associated with many chronic health disorders. We assessed the ability of various natural substances, commonly referred to as “CHO blockers,” to influence starch and sucrose absorption in vivo in ninety-six rats and two pigs. These natural enzyme inhibitors of amylase/sucrase reportedly lessen breakdown of starches and sucrose in the gastrointestinal tract, limiting their absorption. To estimate absorption, groups of nine SD rats were gavaged with water or water plus rice starch and/or sucrose; and circulating glucose was measured at timed intervals thereafter. For each variation in the protocol a total of at least nine different rats were studied with an equal number of internal controls on three different occasions. The pigs rapidly drank CHO and inhibitors in their drinking water. In rats, glucose elevations above baseline over four hours following rice starch challenge as estimated by area-under-curve (AUC) were 40%, 27%, and 85% of their internal control after ingesting bean extract, hibiscus extract, and l-arabinose respectively in addition to the rice starch. The former two were significantly different from control. L-Arabinose virtually eliminated the rising circulating glucose levels after sucrose challenge, whereas hibiscus and bean extracts were associated with lesser decreases than l-arabinose that were still significantly lower than control. The glucose elevations above baseline over four hours in rats receiving sucrose (AUC) were 51%, 43% and 2% of control for bean extract, hibiscus extract, and L-arabinose, respectively. Evidence for dose-response of bean and hibiscus extracts is reported. Giving the natural substances minus CHO challenge caused no significant changes in circulating glucose concentrations, indicating no major effects on overall metabolism. A formula combining these natural products significantly decreased both starch and sucrose absorption, even when the CHO were given simultaneously. These results support the hypothesis that the enzyme inhibitors examined here at reasonable doses can safely lower the glycemic loads starch and sucrose.
J Nutr. 2001 Mar;131(3):796-9.
Faculty of Human and Cultural Studies, Tezukayama Gakuin University Sakai, Osaka 590-0113, Japan.
L-Arabinose is a natural, poorly absorbed pentose that selectively inhibits intestinal sucrase activity. To investigate the effects of L-arabinosefeeding on lipogenesis due to its inhibition of sucrase, rats were fed 0-30 g sucrose/100 g diets containing 0-1 g L-arabinose/100 g for 10 d. Lipogenic enzyme activities and triacylglycerol concentrations in the liver were significantly increased by dietary sucrose, and arabinosesignificantly prevented these increases. Arabinose feeding reduced the weights of epididymal adipose tissue. Moreover, plasma insulin and triacylglycerol concentrations were significantly reduced by dietary L-arabinose. These findings suggest that L-arabinose inhibits intestinal sucrase activity, thereby reducing sucrose utilization, and consequently decreasing lipogenesis.
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Nutr J. 2011 May 6;10:42. doi: 10.1186/1475-2891-10-42.
Integrative Health Technologies, Inc. San Antonio, TX 78209, USA. firstname.lastname@example.org
A growing body of research suggests that elevated circulating levels of glucose and insulin accelerate risk factors for a wide range of disorders. Low-risk interventions that could suppress glucose without raising insulin levels could offer significant long-term health benefits.
To address this issue, we conducted two sequential studies, the first with two phases. In the first phase of Study 1, baseline fasting blood glucose was measured in 20 subjects who consumed 70 grams of sucrose in water and subsequently completed capillary glucose measurements at 30, 45, 60 and 90 minutes (Control). On day-2 the same procedure was followed, but with subjects simultaneously consuming a novel formula containing l-arabinose and a trivalent patented food source of chromium (LA-Cr) (Treatment). The presence or absence of the LA-Cr was blinded to the subjects and testing technician. Comparisons of changes from baseline were made between Control and Treatment periods. In the second phase of Study 1, 10 subjects selected from the original 20 competed baseline measures of body composition (DXA), a 43-blood chemistry panel and a Quality of Life Inventory. These subjects subsequently took LA-Cr daily for 4 weeks completing daily tracking forms and repeating the baseline capillary tests at the end of each of the four weeks. In Study 2, the same procedures used in the first phase were repeated for 50 subjects, but with added circulating insulin measurements at 30 and 60 minutes from baseline.
In both studies, as compared to Control, the Treatment group had significantly lower glucose responses for all four testing times (AUC=P<0.0001). Additionally, the Treatment was significantly more effective in lowering circulating insulin after 60 minutes from baseline (AUC=P=<0.01). No adverse effects were found after acute sucrose challenge or in those who consumed LA-Cr daily for four weeks.
As compared to a placebo control, consumption of a LA-Cr formula after a 70-gram sucrose challenge was significantly more effective in safely lowering both circulating glucose and insulin levels.
Clinical Trials.gov, NCT0110743.
Am J Clin Nutr. 2011 Aug;94(2):472-8. doi: 10.3945/ajcn.111.014225. Epub 2011 Jun 15.
Department of Human Nutrition, University of Copenhagen, Frederiksberg C, Denmark.
On the basis of results in cell cultures, rodents, and pigs, l-arabinose may inhibit intestinal sucrase activity and thereby delay sucrose digestion.
The objective was to investigate the dose-response effects of l-arabinose on intestinal sucrase activity in vitro and glucose tolerance, appetite, and energy intake in humans.
In vitro, Caco-2 cells were cultured for 21 d, homogenized, and used as an enzyme preparation with sucrose as substrate in concentrations from 7 to 280 mmol/L with 0.84, 1.4, and 2.8 mmol l-arabinose/L as inhibitor. Released glucose was measured after 30 min. In the human studies, 15 healthy men participated in a randomized, double-blind, crossover study. Sucrose beverages (75 g in 300 mL) supplemented with 0%, 1.3%, 2.7%, and 4% by weight of l-arabinose were tested at breakfast. Blood for the measurement of glucose, insulin, C-peptide, incretin hormones, and triacylglycerol was collected under fasting conditions and for 3 h postprandially. Postprandial appetite sensations and energy intake at lunch were registered.
In vitro, the addition of l-arabinose resulted in uncompetitive inhibition of sucrase activity. In the human studies, supplementation with 4% l-arabinose produced an 11% lower glucose peak, a 33% lower and delayed insulin peak, a 23% reduction in the incremental area under the curve (iAUC) for insulin, a 23% lower and delayed C-peptide peak, a 9% reduction in the iAUC for C-peptide, a 53% increase in the iAUC for glucagon-like peptide-1 (GLP-1), and a 28% reduction in the iAUC for glucose-dependent insulinotropic polypeptide. No effects on triacylglycerol, gastrointestinal symptoms, appetite ratings, or energy intake were observed.
l-Arabinose inhibits sucrase activity from Caco-2 cells; 4% l-arabinose in sucrose beverages reduces postprandial glucose, insulin, and C-peptide responses and enhances the GLP-1 response in humans without gastrointestinal adverse effects. This trial is registered at clinicaltrials.gov as NCT00302302.