Amylase Inhibitors

Also indexed as: Phaseolamin, Starch Blockers, Wheat Amylase Inhibitor, White Kidney Bean Extract

What are they?

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

Purified starch blocker extracts, when given with a starchy meal, have also been shown to reduce the subsequent rise in blood sugar levels of both healthy people and diabetics.¹⁰ ¹¹ ¹² ¹³ This effect could be helpful in the treatment of blood sugar disorders.

Where are they found?

Amylase inhibitors can be extracted from several types of plants, especially those in the pulse 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):

Science Ratings

Health Concerns

Type 1 diabetes

Type 2 diabetes

Weight loss and obesity

Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars

Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star

For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

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 diarrhoea due to the effects of undigested starch in the colon.¹⁴ ¹⁵ 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
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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.

12. Lankisch M, Layer P, Rizza RA, DiMagno EP. Acute postprandial gastrointestinal and metabolic effects of wheat amylase inhibitor (WAI) in normal, obese, and diabetic humans. Pancreas 1998;17:176–81.

13. Holt PR, Thea D, Yang MY, Kotler DP. Intestinal and metabolic responses to an alpha-glucosidase inhibitor in normal volunteers. Metabolism 1988;37:1163–70.

14. 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.

15. Boivin M, Flourie B, Rizza RA, et al. Gastrointestinal and metabolic effects of amylase inhibition in diabetics. Gastroenterology 1988;94:387–94.

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires March 2007.

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