White kidney bean is a variety of the common bean (Phaseolus vulgaris), which contains a protein (α-amylase blocker) that blocks the breakdown and digestion of starch.
The active ingredient in white kidney beans which gets extracted is called phaseolus vulgaris, which effectively prevents the pancreas from secreting amylase. If 1.5 grams of the supplement is taken with a carb heavy meal, over half the calories coming from complex, starchy carbs will not get digested and instead will ferment in your intestines. The only side effect most people experience from this process is slight bloating and sometimes excessive gas.
White bean extract is widely marketed as a weight loss aid. The product is also purported to prevent obesity and reduce abdominal fat.
The main active compounds of white kidney bean extract are:
Other white kidney bean compounds that might be present in small amounts are:
Specification of White Kidney Bean Extract
Benefits & Applications of White Kidney Bean Extract
The α-amylase blocker found in white kidney beans, α-AI1, is active against human α-amylases. This carbohydrate blocker binds to the α-amylase enzyme and prevents the access of starch. As a result, starch cannot be degraded and fewer simple sugars are absorbed by the intestines.
In two experiments, subjects who took 1,500 mg and 750 mg of Phase 2 with their meal absorbed 1/3 and 2/3 of the carbohydrates, respectively, compared to the control group (DB-RCT of 11 and 7 subjects)
Beanblock (100 mg), taken with a meal after a 12 hour fast, reduced appetite, production of the hunger hormone ghrelin, and glucose and insulin rises in the blood (DB-RCT of 12 healthy individuals).
A combination of bean and artichoke extracts reduced appetite and blood sugar levels after meals (2-month DB-RCT of 39 overweight subjects) .
Beanblock supplementation reduced appetite, body weight, waist size, and oxidative damage (50 mg 2x/day for 12 weeks, DB-RCT of 60 overweight individuals) .
In two rat studies and one mice study, intake of Beanblock reduced food consumption
Phase 2 (two 150 mg capsules, a 3x/day for 9 months) increased the elimination of fats (triglycerides) in feces and reduced the levels of cholesterol and the protein that carries it to the blood vessels (LDL) in the blood (DB-RCT of 62 overweight and obese individuals) .
Phase 2 (1,500 mg, 2x/ day for 8 weeks) had no effect on weight loss but reduced blood triglyceride levels (DB-RCT of 27 obese subjects)
The α-amylases produced by the salivary glands have the following effects in the mouth:
By blocking α-amylases, white kidney bean extract may help prevent cavities and bleeding gums.
Non-digested starch may act similarly to fiber in the large intestine and thus help prevent colon cancer .
Rats given a cancer-causing compound had lower incidences of colon cancer and multiplying tumor cells when fed a diet containing beans compared to rats on a regular diet.
A purified white kidney bean lectin prevented cancer cell growth and increased cell death (skin and liver cancer cell lines) .
Bean extract reduced the clumping of platelet cells. White kidney bean extract may thus reduce the formation of blood clots, although studies in humans are needed to verify these findings.