Lowering the glycemic index of white bread using a white bean extract.
BACKGROUND
Phase 2((R)) 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)


CONCLUSIONS
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.


BACKGROUND
Trial Registration: ISRCTN50347345.
Udani
Jay K
JK
Medicus Research LLC, Northridge, CA 91325, USA. jay.udani@medicusresearch.com
Singh
Betsy B
BB
Barrett
Marilyn L
ML
Preuss
Harry G
HG
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001939:Bread; D018592:Cross-Over Studies; D019587:Dietary Supplements / Q000009:adverse effects; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D038321:Glycemic Index; D006801:Humans; D008297:Male; D027805:Phaseolus / Q000009:adverse effects; D008517:Phytotherapy / Q000009:adverse effects; D010936:Plant Extracts / Q000008:administration & dosage* / Q000009:adverse effects; D019518:Postprandial Period; D012639:Seeds / Q000009:adverse effects; D011795:Surveys and Questionnaires; D055815:Young Adult; D000516:alpha-Amylases / Q000037:antagonists & inhibitors
D001786:Blood Glucose; D004791:Enzyme Inhibitors; C484568:Phase2 starch neutralizer; D010936:Plant Extracts; D000516:alpha-Amylases