Myths and Facts
White Bean ExtractJanuary 11, 2017 /
Dr. Oz announced on his popular television show that like raspberry ketones, white bean extract will “boost” your metabolism. He purports that taking 500 milligrams (mg) prior to eating a large meal will prevent absorption of the carbohydrate. If you tolerate 500 mg/day, he recommends that you increase it to 500 mg twice a day.
Research at the Mayo Clinic
In the early 1980s, several products containing bean amylase inhibitors were introduced, but these preparations were found to have insufficient enzyme-inhibiting activity and issues with potency and stability. A research group at the Mayo Clinic then developed a partially purified white bean product and published a series of studies about it. The product was found to inactivate amylase activity in vitro, and studies showed that it decreased the digestion of starch in a dose-dependent fashion.
When volunteers were given the product, it increased the postprandial delivery of carbohydrates to the distal small bowel by 22% to 24% and increased hydrogen concentrations in the breath for 30 to 90 minutes postprandially (this meant that the colonic bacteria were fermenting the carbohydrate). The uptick in postprandial plasma glucose also was reduced by 85%. The extract significantly decreased the postprandial levels of insulin, C-peptide, and gastric inhibitory polypeptide. A follow-up study demonstrated a decrease in the postprandial increases in plasma glucose and insulin levels among people with diabetes. A 3-week study that enrolled six individuals with noninsulin-dependent diabetes resulted in a 30% reduction of their postprandial plasma glucose levels when given 4 to 6 grams with each meal (a rather high dose).
However, peer-reviewed, randomized controlled, double-blind trials have not concluded that white bean extract is a weight loss miracle.
A clinical trial using a proprietary fractionated white bean extract
Udani and Singh published Blocking Carbohydrate Absorption and Weight Loss: A Clinical Trial Using a Proprietary Fractionated White Bean Extract in 2007 in Alternative Therapies in Health and Medicine. In the study, patients were weighed at baseline and at the conclusion of the study. Waist measurements also were recorded at baseline and at completion of the trial. The study included 25 patients 18 to 40 years of age with a body mass index (BMI) of between 25 and 31. All participants agreed to maintain diet and exercise modification and to come to periodic follow-up visits. All of the women were asked to use adequate birth control.
The participants took 1000 mg of fractionate white bean extract with breakfast and lunch for 4 weeks in combination with a weight loss program. The researchers reported a weight loss of 6 pounds (lb) for the test group and 4.7 lb for the control group after completion of the study. Neither the difference between groups in terms of weight lost nor the decrease in waist measurement was significantly different.
A clinical trial using Phase 2™ brand proprietary fractionated white bean extract
Udani et al published a study in 2004 entitled Blocking Carbohydrate Absorption and Weight Loss: A Clinical Trial Using Phase 2 Brand Proprietary Fractionated White Bean Extract. Participants were weighed at baseline and then every 2 weeks during the 8-week study. The study included 39 participants between 20 and 69 years of age with a BMI of 30 to 43. They took 1500 mg of Phase Two white bean extract with lunch and dinner for 8 weeks and followed a prescribed diet program. All of the women in the study agreed to take adequate contraception, and all participants were asked to not take any drugs used to treat obesity. The test group lost an average of 3.79 lb during the 8-week study, while the control group lost an average of 1.65 lb. Analysis showed no statistical difference.
Influences of Phaseolus vulgaris extract on body composition of overweight men and women
Celleno et al measured weight loss, body composition, waist circumference, hip circumference, and right thigh circumference at baseline and at completion of the study. The study was published in 2007 in the International Journal of Medical Sciences. Sixty participants between 20 and 45 years of age were included in this study. They were all 5 to 15 kilograms (kg) overweight, had stable body weight for at least the previous 6 months, and were in good general health with no ongoing drug treatment. They all agreed to follow the prescribed diet, to avoid other products for weight loss, and to avoid major lifestyle changes for the duration of the study. For 30 days, they took 445 mg of Phaseolus vulgaris once daily before eating their largest meal containing the most carbohydrates and followed a prescribed diet program.
When weight loss between the test group and the control group was compared, data did show a significant difference. Furthermore, the major weight changes were brought about more by fat loss rather than loss of nonfat body mass. The test group lost 2.93 lb ±1.16 lb, while the control group lost 0.35 lb ±0.38 lb. The control group lost 2.4 lb ±0.67 lb of fat mass, while the control group lost 0.16 lb ±0.33 lb of fat mass. The control group lost 0.53 lb ±0.45 lb of lean body mass, while the control group lost 0.19 lb ±0.17 lbs.
Enhanced weight loss from a dietary supplement containing standardized Phaseolus vulgaris extract
Wu et al carried out a randomized, double-blind, placebo-controlled trial at the Zhejiang University in China. A total of 101 healthy subjects between 20 and 50 years of age with a BMI of between 25 and 40 were included. The participants took two capsules containing 1000 mg each of Phase 2® Starch Neutralizer. Subjects in the active group lost significantly more body weight and waist measurement at both month 1 and 2 than the placebo group. Forty-seven of 51 subjects in the active group lost weight (92%) after 2 months, compared to 31 in the placebo group (62%). The average weight loss in the active group was 1.9 kg compared to a 0.4-kg loss in the placebo group. Hip measurement did not change significantly during the 2 months of study. However, waist size decreased significantly more in the active group (-1.9 centimeters [cm] vs -0.4 cm in the placebo group).
It is thought that Phase 2® Carb Controller (Pharmachem Laboratories, Inc, Kearny, NJ) is more effective for weight loss than other forms of white bean extract. This product was used in both the Celleno and Wu studies.
Precautions, side effects, and dosage
The extract is not recommended for people with diabetes or for pregnant women, because it could cause hypoglycemia. Mild nausea and diarrhea are the most common side effects. No significant adverse effects were reported in any of the studies discussed in this article.
A typical dose of Phase 2 is 500 mg to 1000 mg taken before each of the three meals/day.
References and recommended readings
Celleno L, Tolaini MV, D’Amore A, Perricone NV, Preuss HG. A dietary supplement containing standardized Phaseolus vulgaris extract influences body composition of overweight men and women. Int J Med Sci. 2007;4(1):45-52.
Udani J, Hardy M, Madsen DC. Blocking carbohydrate absorption and weight loss: a clinical trial using Phase 2 brand proprietary fractionated white bean extract. Altern Med Rev. 2004;9(1):63-69.
Udani J, Singh BB. Blocking carbohydrate absorption and weight loss: a clinical trial using proprietary fractionated white bean extract. Altern Ther Health Med. 2007;13(4):32-37.
Weight loss weapon: carb-cutting enzyme stopped by bean extract, endocrinologists say. ScienceDaily® Web site. http://www.sciencedaily.com/videos/2007/0404-weight_loss_weapon.htm. Accessed November 1, 2013.
Wu X, Xu X, Shen J, Perricone N, Preuss H. Enhanced weight loss from a dietary supplement containing standardized Phaseolus vulgaris extract in overweight men and women. J Appl Res. 2010;10:73-79.