Many foods can cause gassiness, including beans (legumes), broccoli, cabbage, onions, and whole grains. This occurs because these foods contain complex carbohydrates that are not entirely broken down in the digestive tract, and instead serve as food for intestinal bacteria. These bacteria produce hydrogen and carbon dioxide gas as they digest the carbohydrates. While everyone develops intestinal gas to some extent, certain people have an intolerance of complex carbohydrates and develop relatively more severe symptoms.1 Use of alpha-galactosidase has been advocated as a treatment for both complex carbohydrate intolerance and ordinary gassiness. This enzyme helps break down complex carbohydrates. When taken as a supplement, it may enhance the digestive process and thereby deprive gas-producing bacteria of fuel to work on.
Alpha-galactosidase is ordinarily manufactured by the body and is not a nutrient. It is found in particularly high quantities in the yeast Aspergillus niger, the source of commercial products.
A typical supplemental dosage of alpha-galactosidase provides 450 GalU ( galactosidase units) per meal.
Although alpha-galactosidase is widely marketed as an over-the-counter treatment to prevent intestinal gas, there is only limited evidence that it really works. In two preliminary double-blind, controlled trials enrolling a total of 39 people, use of alpha-galactosidase along with a meal of beans significantly reduced symptoms of excess gas.2,3 Two other relevant trials were also small, and suffered from significant design flaws.3,4 Larger and more strictly designed studies will be necessary to determine whether alpha-galactosidase is truly an effective treatment for reducing intestinal gas.
Although alpha-galactosidase appears to be safe for people in normal health, there are potential concerns involving people with diabetes as well as those with a rare condition named galactosemia.
Alpha-galactosidase breaks down complex carbohydrates into easily absorbed sugars. This may raise blood sugar levels in people with diabetes. One study found that use of alpha-galactosidase supplements reduced the effectiveness of the diabetes drug acarbose, an alpha-glucosidase inhibitor drug.5 For this reason, people with diabetes who are using alpha-glucosidase inhibitors should avoid alpha-galactosidase supplements. In addition, it is theoretically possible that alpha-galactosidase might increase blood sugar levels in people with diabetes who are not taking alpha-glucosidase inhibitors, but this has not been thoroughly evaluated.
People with the genetic condition galactosemia should also avoid alpha-galactosidase as it could, in theory, worsen symptoms of the disease.
Safety in young children, pregnant or nursing women, or people with severe liver or kidney disease has not been established.
If you are taking the drugs acarbose (Precose) or miglitol (Glyset) for treatment of diabetes, use of alpha-galactosidase may decrease their effectiveness.
1. Levine B, Weisman S. Enzyme replacement as an effective treatment for the common symptoms of complex carbohydrate intolerance. Nutr Clin Care. 2004;7:75–81.
2. Solomons NW, Vettorazzi L, Grazioso C. Use of an oral alpha-galactosidase to control gastrointestinal symptoms from legume oligosaccharides in bean-intolerant subjects: a doubly masked, controlled therapeutic trial. Clin Res. 1991;39:428A.
3. Ganiats TG, Norcross WA, et al. Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance. J Fam Pract. 1994;39:441–445.
4. Solomons NW, Guerrero AM, Zepada E, Grazioso C. The efficacy of an oral alpha-galactosidase to promote oligosaccharide hydrolysis and to reduce intolerance symptoms after ingestion of beans: a dose response trial. ClinRes. 1991;39:655A.
5. Lettieri JT, Dain B. Effects of beano on the tolerability and pharmacodynamics of acarbose. Clin Ther. 1998;20:497–504.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 10/12/2017