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
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3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
This supplement has been used in connection with the following health conditions:
1,200 to 2,400 mg per day of white kidney bean extract
Amylase inhibitors, like phaseolamin from white kidney beans, reduce digestion and absorption of dietary carbohydrates and may aid in weight loss.
Amylase inhibitors are also known as starch blockers because they interfere with digestion of dietary starches and other complex carbohydrates, slowing digestion in general, reducing absorption of glucose, and preventing blood glucose spikes. Phaseolamin is an amylase inhibitor from white kidney beans (Phaseolus vulgaris) and has been widely studied for its potential to support weight loss. In a placebo-controlled trial that included 120 participants with obesity, those treated with 2,400 mg per day of white kidney bean extract lost 2.24 kg (4.9 pounds) after 35 days, while those taking placebo lost only 0.29 kg (0.6 pounds. In another trial, mildly overweight adults with stable weight for six months or longer took either 445 mg of white kidney bean extract or placebo daily for 30 days; those taking white kidney bean extract lost 2.93 kg (6.4 pounds), while those taking placebo lost 0.35 kg (0.8 pounds). They also lost more body fat and had greater reductions in waist, hip, and thigh circumferences. A meta-analysis that included 11 clinical trials (including some unpublished data from supplement manufacturers) with a combined total of 573 participants found white kidney bean extract, at a dose of at least 1,200 mg per day for a minimum of four weeks, can promote weight loss in people with overweight and obesity. A separate meta-analysis in the same publication, which included three trials with a combined total of 110 subjects, found white kidney bean extract also reduces body fat.
Type 1 Diabetes
Refer to label instructions
Amylase inhibitors, taken with meals, may reduce the usual rise in blood sugar levels in people with diabetes.
Substances that inhibit amylase, the digestive enzyme required to break down dietary starches into absorbable glucose units, can reduce the usual post-meal rise in blood sugar levels in both healthy people and people with diabetes. Amylase inhibitors occur naturally in foods such as whole grains and legumes, as well as in many culinary herbs and spices and medicinal herbs, possibly contributing to their anti-diabetic effects. While some food and herbal extracts with amylase-inhibiting effects have shown promise in animal research, their benefits for type 1 diabetes await confirmation in clinical trials.
Type 2 Diabetes
Varies depending on source
Amylase inhibitors from various medicinal herbs and plant foods may reduce the usual after-meal rise in blood glucose levels in people with diabetes.
Amylase inhibitors are substances that reduce the activity of amylase, the digestive enzyme required to break down dietary starches into absorbable glucose. Many plants and plant foods, including vegetables and legumes, contain amylase-inhibiting compounds that may be useful in preventing and treating type 2 diabetes. For example, adding beans to a serving of rice reduces the rise in blood glucose, an effect that may be due in part to the amylase-inhibiting action of beans. A review of clinical trials reported that taking 1,500 to 3,000 mg of an amylase-inhibiting extract from white beans (Phaseolus vulgaris) before meals has been shown in multiple studies to reduce post-meal blood glucose levels and may promote weight loss. However, this review and most of the studies it included were funded by the manufacturer of the bean extract. Its usefulness as a therapy for type 2 diabetes has not been tested.
How It Works
How to Use It
Depending on the potency of the amylase inhibitors , typical intake is 1,500 to 6,000 mg before meals.
Where to Find It
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 are not essential nutrients and are not normally produced in the body, so no deficiency is possible.
Interactions with Supplements, Foods, & Other Compounds
Diabetics taking medications to lower their blood sugar should not take amylase inhibitors without first consulting a doctor.
Interactions with Medicines
High amounts of amylase inhibitors may cause diarrhea due to the effects of undigested starch in the colon.10, 11
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.
Last Review: 06-08-2015
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The information presented by TraceGains 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 pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2023.