Joe A. Vinson, Ph.D.
Department of Chemistry
University of Scranton

Background
Amylase is a digestive tract enzyme, which breaks down starch into small units capable of being further degraded to glucose, which is used for fuel for normal metabolism and body homeostasis. Clinical use of inhibitors of amylase activity has widespread appeal because a controlled reduction of starch digestion could influence carbohydrate uptake in diabetes and obesity, the latter of which is a current problem with 20% of the US population. Of course obesity is also linked to a greater risk of diabetes. A search in the National Library of Medicine Database reveals that there are 1098 articles concerning amylase inhibition. About 15 years ago there were a number of articles concerning the use of commercial bean-derived extracts. Also there were several articles indicating that some of these products, which were good in vitro inhibitors, were not effective when given to humans. Possible reasons for this failure were 1) insufficient activity; 2) destruction in the gastrointestinal tract; 3) suboptimal pH conditions; and 3) different gastric emptying rates of starch and inhibitor. A comprehensive experimental investigation by a group at the Mayo Clinic in 1985 found that the major reason commercial bean amylase inhibitors have failed to influence starch digestion in humans is their low anti-amylase activity. Some inhibitors also have side effects such as diarrhea and an increase in intestinal gas. We have investigated the effectiveness of a new commercial bean extract (Bio-Phase 2250™ ).

Protocol
Five males and five females (ages 21 to 57) participated in a double-blind placebo controlled crossover study with informed consent. All subjects were employees at a commercial clinical laboratory and went about their duties as secretaries and technicians during the study. After an overnight fast, the participants were sampled for blood and then given in a random manner either 1) placebo consisting of 4 slices of white bread (60 grams of carbohydrate), 42 grams of soybean oil margarine and 4 grams of Sweet N'Low spread on the bread; 2) experimental comprising the placebo plus 1.5 grams of Bio-Phase 2250™. Plasma glucose wasmeasured, by a commercial enzyme kit (Sigma Chemical Company), from blood drawn at baseline every 30 minutes for 4 hours. After 1 week the regimen was repeated with the other supplement.

Results and Discussion
The subjects were normoglycemic as measured by fasting glucose concentration, which averaged 98 mg/dl for the placebo and 104 for the Bio-Phase 2250® . From 60 to 120 minutes (as seen in the accompanying figure) the change in plasma glucose of the Bio-Phase 2250™ group from the baseline was ½ to 1/3 of the level of the placebo group. Bio-Phase 2250™ consumption caused the plasma glucose to return to baseline values 20 minutes earlier than the placebo without Bio-Phase 2250™. The average area under the plasma glucose-time curve from 0 to 150 minutes, which is a measure of absorption and metabolism, was 57% lower with Bio-Phase 2250™. Plotting the average change in glucose concentration from 30 minutes to 210 minutes, the area under the curve was positive for the placebo but negative for Bio-Phase 2250™ . This indicates that very little of the glucose from the starch in the bread was absorbed when co-ingested with Bio-Phase 2250™ and the glucose was cleared very rapidly. No side effects were observed with this product. The promising positive preliminary results of this single dose pilot study need to be confirmed. More control of physical activity is required to decrease the variability of plasma glucose between subjects. Ingestion of Bio-Phase 2250™ with a conventional meal should be examined. Other groups such as diabetic and obese should be studied with a single dose and also in a long-term supplementation study.