Studies reveal that a partially purified white bean amylase inhibitor reduces starch digestion and inactivate intraduodenal amylase in humans by 94 to 99.9%. A dose-dependent inhibition of alpha-amylase activity on perfusion of the partially purified inhibitor (2.0, 3.5 or 5 mg/ml at the rate of 5 ml/min) into the duodenum was observed (Layer et al.,2 1985).
Blood sugar management
The alpha-amylase inhibitory activity of Fabenol® also has implications in blood sugar management. In a pilot study, after-meal blood sugar levels were measured in a group of healthy subjects after taking 50 g of carbohydrate in the form of wheat, rice and other high-carbohydrate plant foods. Phaseolus vulgaris inhibited the average post-ingestion spike in blood sugar by a remarkable 67% (Dilawari et al.,1 1981).
Excess starch in the diet is converted into glucose in GI tract and upon absorption is converted to fats and stored in the body. An alpha-amylase inhibitor, inhibits the digestion of starch, thereby potentially improving postprandial glucose tolerance in people with low glucose tolerance.
A remarkable reduction in postprandial increases in plasma concentrations of glucose and insulin in both normal subjects and diabetic patients compared to placebo. On comparing with placebo, the administration of alpha-amylase inhibitor with 50 g starch, reduced postprandial increases in plasma concentrations of glucose and insulin in both normal subjects and those with diabetes (Layer et al.,3 1986).