4 replies to this topic

[Skötkonung]

http://www.ncbi.nlm....les/PMC2776021/

Background
Phase 2^® is a dietary supplement derived from the common white kidney bean (Phaseolus vulgaris). Phase 2 has been shown to inhibit alpha-amylase, the complex carbohydrate digesting enzyme, in vitro. The inhibition of alpha-amylase may result in the lowering of the effective Glycemic Index (GI) of certain foods. The objective of this study was to determine whether the addition of Phase 2 would lower the GI of a commercially available high glycemic food (white bread).
Methods
An open-label 6-arm crossover study was conducted with 13 randomized subjects. Standardized GI testing was performed on white bread with and without the addition of Phase 2 in capsule and powder form, each in dosages of 1500 mg, 2000 mg, and 3000 mg. Statistical analysis was performed by one-way ANOVA of all seven treatment groups using unadjusted multiple comparisons (t tests) to the white bread control.
Results
For the capsule formulation, the 1500 mg dose had no effect on the GI and the 2000 mg and 3000 mg capsule doses caused insignificant reductions in GI. For the powder, the 1500 mg and 2000 mg doses caused insignificant reductions in the GI, and the 3000 mg dose had a significant effect (-20.23 or 34.11%, p = 0.023)
Conclusion
Phase 2 white bean extract appears to be a novel and potentially effective method for reducing the GI of existing foods without modifying their ingredient profile.

http://www.ncbi.nlm....les/PMC1796956/

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, 2000- to 2200-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.

I wonder if this could be helpful in reducing damage done by occasional "cheat" meals? Has anyone tried this?

[Sillewater]

At the nutrition store I work at we sell products like this (carb-blockers). Wouldn't the undigested carbs make it into the large intestines causing problems? (feeding the "bad" bacteria)

[Skötkonung]

At the nutrition store I work at we sell products like this (carb-blockers). Wouldn't the undigested carbs make it into the large intestines causing problems? (feeding the "bad" bacteria)

That's my suspicion. They would simply ferment and cause gas? I am not seeing this in the reviews for these products.

[Sillewater]

http://www.iherb.com...-Gels/3184?at=0

For this product there are two reviews mentioning gas.

Gastroenterology. 1988 Feb;94(2):387-94.
Gastrointestinal and metabolic effects of amylase inhibition in diabetics.
Boivin M, Flourie B, Rizza RA, Go VL, DiMagno EP.

Division of Gastroenterology, Mayo Clinic, Rochester, Minnesota.
A partially purified amylase inhibitor given with a single meal causes maldigestion of carbohydrate, increases delivery of carbohydrate to the ileum, and reduces postprandial plasma glucose. To determine the effect of more prolonged administration of the inhibitor on gastrointestinal function and carbohydrate tolerance, we studied 6 non-insulin-dependent diabetics (3 previously treated with oral agents and 3 treated with diet alone) for 3 wk while they ate a weight-maintenance diet. Patients taking oral agents continued them during the first week. During the second week, 4-6 g of the inhibitor was given with each meal. Capillary blood glucose concentration was measured before each meal and 90 min postprandially. On the last day of each week venous blood samples for glucose, hormones, and lactic acid analysis and a quantitative stool culture were obtained. Total carbohydrate absorption was estimated by comparing postprandial breath hydrogen on study days 7, 14, and 21 with breath hydrogen after ingesting 15 g of lactulose on days 0, 15, and 22. There 24-h stools were collected and weighed at the end of each week and analyzed for carbohydrate, lactic acid, short-chain fatty acids, pH, dry matter, amylase, and fat. The inhibitor significantly (p less than 0.05) reduced postprandial plasma glucose, C-peptide, insulin, and gastric inhibitory polypeptide concentrations, significantly increased (p less than 0.05) breath hydrogen excretion, and caused carbohydrate malabsorption. Diarrhea occurred the first day the inhibitor was ingested, but thereafter cessation of diarrhea was associated with changes in the metabolism of carbohydrate by colonic flora. As the amylase inhibitor improves carbohydrate homeostasis and is not associated with continuing diarrhea, it may be a useful adjuvant in the treatment of patients with non-insulin-dependent diabetes mellitus.

PMID: 2446948 [PubMed - indexed for MEDLINE]

This study mentions chronic effects on rats:

Nutrition. 1999 Feb;15(2):123-9.
Effect of prolonged intraluminal alpha-amylase inhibition on eating, weight, and the small intestine of rats.
Kataoka K, Dimagno EP.

Division of Gastroenterology and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
Effects of chronic intraluminal amylase inhibition on eating and the digestive system are unclear. In growing rats, we determined the effect of ingesting a wheat amylase inhibitor (AI) on eating, weight, small intestinal mucosal growth, and disaccharidases. Three groups of 12 rats received AI, were pair-fed controls (PFC), or had free access to food (FAC). After measuring food intake and body and stool weight for 21 d, rats were decapitated and the small intestine was divided into four segments. AI and PFC rats had similar food intake, weight gain, and stool output, but these were less than FAC rats (P < 0.005). AI rats ate less (P < 0.001) than PFC during the light cycle and less than FAC rats during darkness. Mucosal DNA and RNA were reduced (P < 0.05) in the upper small intestine of AI and PFC rats compared with FAC rats. Mucosal weight, RNA, and disaccharidase activities were greater (P < 0.01) in the ileum of AI rats compared with PFC and FAC rats. AI alters the amount and pattern of food intake, reduces weight gain, upper small intestinal mucosal weight, protein and DNA, and increases distal small intestinal mucosal weight, RNA, and disaccharidases. AI likely causes these effects by inducing satiety and increasing carbohydrate delivery to the distal intestine.

PMID: 9990576 [PubMed - indexed for MEDLINE]

But since we are talking about intermittent use might not be a problem.

I'm just wondering what the difference in fermentation would be between fiber vs. starches in the colon.

[JBForrester]

Have any of you tried this as a supplement?