Phaseolamin is a generic name for a proteinaceous inhibitor of the enzyme alpha-amylase that is made from white beans. A number of amylase inhibitors from white beans have been marketed over the years as weight control remedies.
As reported in the Journal of the American Medical Association (JAMA), early phaseolamin products did not have sufficient potency or stability to effect any in vivo changes. In addition, impurities contained therein caused complaints of GI distress including flatulence. In the late 1990s, the first standardized starch blocker, "Phase 2 Carb Controller" (also known as StarchLite), was developed . Phase 2 is a fractionated white kidney bean extract that has been clinically shown in 13 studies to delay the digestion and absorption of starch calories. Phase 2 neutralizes some of the digestive enzyme alpha amylase, temporarily delaying the digestion and absorption of carbohydrates, allowing a portion of them to pass through the system before they can be converted into glucose, and then fat. Phase 2 is generally recognized as safe (GRAS) and usually does not cause side effects. Phase 2 is available as an ingredient that can be formulated in a variety of nutritional supplements, foods and beverages. It is also sold as "StarchLite" in Europe. In 2006, the Food and Drug Administration, based on clinical data and information submitted to the agency, announced that it does not object to weight control and starch reduction claims for Phase 2, and finished dietary supplement products containing the ingredient. With this announcement, Phase 2 became the first nutritional ingredient with two permitted structure/function claims: 1) May assist in weight control when used in conjunction with a sensible diet and exercise, and 2) May reduce the enzymatic digestion of dietary starches.
Clinical trial results
A study was conducted in two phases to determine the safety and efficacy of Phase 2 (IQP-PV-101) in weight management in obese and overweight Caucasian adults. The weight loss phase was a 12-week randomized, double-blind, placebo-controlled study where all subjects followed a strict diet plan; the second phase was the weight maintenance study over 24 weeks, where the subjects’ energy intake was ad libitum. Results showed that those subjects taking Phase 2 lost significantly more weight than those on placebo after 12 weeks. In the weight management phase, 73.5% of participants successfully maintained their body weight after 24 weeks. In addition, after 12 weeks, the active arm in the weight-loss study experienced a statistically significant decrease in their desire as well as in their frequency and strength of food cravings for chocolates and other sweet foods, whereas the placebo group experienced a significant increase in the difficulty in resisting particular types of food. The study was published online in the journal Obesity in 2013.
A double-blind, placebo-controlled study of 60 human subjects showed that those who took Phase 2 lost an average of 6.45 lb (2.93 kg) in 30 days, compared to those on placebo, who lost less than 1 lb (0.45 kg), on average. Those participants on Phase 2 also lost, on average, over 10% of body fat mass, and more than 3% in waist circumference. The study was conducted by Leonardo Celleno MD, Alessandra D’Amore MD, and Maria Toliani of the Cosmetic Research Center in Rome. Analysis was conducted by Harry Preuss MD, Georgetown University Medical Center; and Nicholas Perricone MD, of Clinical Creations, Meriden, Connecticut. The study was published in the International Journal of Medical Sciences, 2007.
A double-blind, placebo-controlled, crossover pilot study of 11 adult human subjects showed that starch absorption averaged 66% less in the group taking Phase 2. The study was conducted by Joe A. Vinson, Ph.D., and Donna M. Shuta, B.S., Department of Chemistry, University of Scranton, April 24, 2002.
A double-blind, human pilot study published in Alternative Therapies in Health and Medicine found that those who ate the most carbohydrates and took a supplement containing Phase 2, lost significantly more weight and inches from their waist than the placebo group. When stratified by total carbohydrate intake, the Phase 2 group lost an average of 8.7 lb (3.9 kg) and 3.3 inches off their waists, while the placebo group lost an average of 1.7 lb (0.77 kg) and 1.3 inches. The results were statistically significant.
In a clinical trial performed by Jay Udani, MD (Assistant Clinical Professor at the UCLA School of Medicine), a randomly selected group of obese subjects were given 1500 mg of Phase 2 twice daily with meals. Over the period of the eight-week trial, which 27 subjects completed, the group using Phase 2 showed an average weight loss of 3.79 pounds (1.72 kg) pounds, compared with an average of 1.65 lb (0.75 kg) for subjects taking a placebo. No adverse effects were observed during the trial. The study was published in Alternative Medicine Review, Volume 9, Number 2, March 2004.
An open-label 6-arm [clarification needed] crossover study with 13 randomized subjects using standardized GI(glycemic index)testing showed that the GI of Wonder brand white bread was significantly reduced by the addition of 3000 mg of the Phase 2/StarchLite white bean extract in powder form with other dosages and formulations trending toward significance. The study was conducted by Jay Udani, MD Medical Director, Medicus Research.
Doubts have been expressed about the efficacy of phaseolamin by Ray and Terry's products, a supplement company connected with Ray Kurzweil. On its website, the company claims to have carried out trials which did not indicate that it worked well.
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- Barbara Grube, Wen-Fen Chong, Pee-Win Chong and Linda Riede. "Weight Reduction and Maintenance with IQP-PV-101: A 12-Week Randomized Controlled Study with a 24-Week Open Label Period". Obesity, published online 2013.
- Celleno L, Tolaini M, D'Amore A, Perricone N, Preuss H (2007). "A Dietary Supplement Containing Standardized Phaseolus vulgaris Extract Influences Body Composition of Overweight Men and Women". International Journal of Medical Sciences 4: 45–52. doi:10.7150/ijms.4.45.
- Jay Udani, MD, Medical Director, Integrative Medicine Program, Northridge Hospital Medical Center, Northridge, CA; Betsy Singh, Ph.D., Dean of Research, Southern California University of Health Sciences (2007). "Blocking Carbohydrate Absorption and Weight Loss: A Clinical Trial Using a Proprietary Fractionated White Bean Extract". Alternative Therapies in Health and Medicine 13 (4): 32–7. PMID 17658120.
- Jay Udani, MD, Mary Hardy, MD, and Damian C. Madsen. "Blocking Carbohydrate Absorption and Weight Loss: A Clinical Trial Using Phase 2 Brand Proprietary Fractionated Bean Extract". Alternative Medicine Review 9 (2).