Also indexed as: Phaseolamin, Starch Blockers, Wheat Amylase
Inhibitor, White Kidney Bean Extract
Amylase inhibitors are also known as starch blockers because they contain substances that
prevent dietary starches from being absorbed by the body. Starches are complex carbohydrates
that cannot be absorbed unless they are first broken down by the digestive enzyme amylase and
other, secondary, enzymes.1 2 They are claimed to be useful for weight loss, but when they were first developed years
ago, research did not find them very effective for limiting carbohydrate
absorption.3 4 5 6 Later, however, highly
concentrated versions of amylase inhibitors did show potential for reducing carbohydrate
absorption in humans.7 8 9
Where are they found?
Amylase inhibitors can be extracted from several types of plants, especially those in the
legume family. Currently available Amylase
inhibitors are extracted from either white kidney
bean or wheat.
Amylase inhibitors have
been used in connection with the following conditions (refer to the
individual health concern for complete information):
Who is likely to be deficient?
Amylase inhibitors are not essential nutrients and are not normally produced in the body,
so no deficiency is possible.
How much is usually taken?
Depending on the potency of the amylase inhibitors , typical intake is 1,500 to 6,000 mg
before meals.
Are there any side effects or interactions?
High amounts of amylase inhibitors may cause
diarrhea due to the effects of undigested starch in the colon.10 11
Diabetics taking medications to lower their blood sugar should not take amylase inhibitors
without first consulting a doctor.
At the time of writing, there were no well-known drug interactions
with amylase inhibitors.
References:1. Marshall JJ, Lauda CM. Purification and properties of phaseolamin, an
inhibitor of alpha-amylase, from the kidney bean, Phaseolus vulgaris. J Biol Chem
1975;250:8030-7.
2. Choudhury A, Maeda K, Murayama R, DiMagno EP. Character of a wheat
amylase inhibitor preparation and effects on fasting human pancreaticobiliary secretions and
hormones. Gastroenterology 1996;111:1313-20.
3. Bo-Linn GW, Santa Ana CA, Morawski SG, Fordtran JS. Starch
blockers—their effect on calorie absorption from a high-starch meal. N Engl J
Med 1982;307:1413–6.
4. Hollenbeck CB, Coulston AM, Quan R, et al. Effects of a commercial
starch blocker preparation on carbohydrate digestion and absorption: in vivo and in vitro
studies. Am J Clin Nutr 1983;38:498–503.
5. Garrow JS, Scott PF, Heels S, et al. A study of 'starch blockers' in
man using 13C-enriched starch as a tracer. Hum Nutr Clin Nutr
1983;37:301–5.
6. Carlson GL, Li BU, Bass P, Olsen WA. A bean alpha-amylase inhibitor
formulation (starch blocker) is ineffective in man. Science 1983;219:393–5.
7. Brugge WR, Rosenfeld MS. Impairment of starch absorption by a potent
amylase inhibitor. Am J Gastroenterol 1987;82:718–22.
8. Boivin M, Zinsmeister AR, Go VL, DiMagno EP. Effect of a purified
amylase inhibitor on carbohydrate metabolism after a mixed meal in healthy humans. Mayo
Clin Proc 1987;62:249–55.
9. Layer P, Carlson GL, DiMagno EP. Partially purified white bean amylase
inhibitor reduces starch digestion in vitro and inactivates intraduodenal amylase in humans.
Gastroenterology 1985;88:1895–902.
10. Boivin M, Zinsmeister AR, Go VL, DiMagno EP. Effect of a purified
amylase inhibitor on carbohydrate metabolism after a mixed meal in healthy humans. Mayo
Clin Proc 1987;62:249–55.
11. Boivin M, Flourie B, Rizza RA, et al. Gastrointestinal and metabolic
effects of amylase inhibition in diabetics. Gastroenterology
1988;94:387–94.