Recently, both amylase inhibitors and glucosidase inhibitors have emerged as potential approaches for weight loss and the treatment of diabetes.
Starch is the arrangement of glucose molecules, and enzymes like amylase and glucosidase break it down into glucose. By inhibiting these enzymes, starch can’t convert fully into glucose, reducing blood sugar spikes and aiding weight loss. This approach is effective primarily for starchy foods like bread and potatoes, and particularly for individuals with less control over their eating habits. However, it doesn’t work for sugary desserts or beverages high in simple sugar.
White kidney bean extract (Phaseolus vulgaris extract) primarily acts as an α-amylase inhibitor. An early clinical trial from 2004 [1] involving obese participants found that after using the extract, the intervention group lost 3.79 pounds, while the control group lost 1.65 pounds.
A 2007 double-blind controlled study [2] with 60 obese participants had them take 445mg of white kidney bean extract or a placebo before meals for 30 days. After the trial, the extract group showed significant improvements in weight, visceral fat, waist circumference, and thigh circumference compared to the control group.
A study by UCLA with 25 participants involved dietary changes and exercise. The intervention group took daily white kidney bean extract while the control group received a placebo. Both groups lost weight over 4 weeks, but the extract group showed greater reduction, particularly among high-carb consumers [3].
A 2014 German study [4] on 100 obese participants divided them into groups for a 12-week intervention. White kidney bean extract led to significantly higher weight loss (2.9kg) compared to the placebo group (0.92kg). The study continued for 24 weeks, with 73.5% of the intervention group maintaining their weight.
Apart from white kidney bean extract, all whole grains inherently contain amylase and glucosidase inhibitors. [5] Virtually every whole grain variety possesses compounds that impede the transformation of starch into glucose, commonly known as antinutrients.
What kinds of starchy foods lack these inhibitors? They are the refined carbohydrate and simple starch choices we commonly consume on a daily basis: white bread, white rice and potatoes.
White kidney bean extract, enriched with α-amylase inhibitors, unquestionably contributes to diminishing the metabolism and absorption of starchy foods, facilitating blood sugar management and aiding in weight loss. Nevertheless, when integrated into a well-balanced diet comprising starchy foods and supplemented by increased physical activity, controlled trials indicate that white kidney bean extract does not offer too much additional advantages.
Whole grains, by their very nature, are replete with ample α-amylase inhibitors and additionally provide the “double assurance” of glucosidase inhibitors, effectively curtailing excessive glucose uptake.
Moreover, whole grains boast substantial dietary fiber content and vital micronutrients, reducing caloric intake while enhancing nutrient absorption. Consequently, selecting whole grains may render investing in white kidney bean extract redundant. It is also pivotal to steer clear of sugary foods and beverages; otherwise, neither white kidney bean extract nor a diet centered around whole grains can genuinely provide assistance.
References:
[2] Celleno, L. et al. (2007). A Dietary supplement containing standardized Phaseolus vulgaris extract influences body composition of overweight men and women. International journal of medical sciences, 4(1), 45–52. https://doi.org/10.7150/ijms.4.45
[3] Udani, J., & Singh, B. B. (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), 32–37.
