Known interactions

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Quick guide to Mai Ya

Scientific Name: Barley

Other Names: Barley Grass, Hordeum vulgare, Mai Ya, Pearl Barley, Scotch Barley

Who is this for?

For medical use, whole barley seeds — and cereals and flour made from them — are being investigated for treating diabetes, high cholesterol, and obesity. Some evidence from separate studies involving laboratory animals and humans suggests that barley seed products in the diet may improve blood sugar levels in individuals with diabetes — possibly because the fiber in barley seeds delays stomach emptying and slows down the absorption of carbohydrates from foods. Like oatmeal, barley seeds contain fiber that dissolves in water and fiber that does not dissolve. Both types that may help to lower cholesterol. In clinical studies, many participants who ate barley or bakery made with barley showed reductions in their total cholesterol, low-density lipoprotein (LDL, the "bad" cholesterol), or triglyceride levels as compared to participants who ate products made with wheat flour. The positive results from some studies were erratic, however, with some participants showing much different results than others on the same diet. In addition, barley seed fiber may help individuals lose weight by creating a feeling of fullness that persists because the fiber swells and stomach contents stay in the stomach longer. Barley seeds may also protect against colon cancer. Generally, the fiber in barley seeds has been shown to help prevent colon cancer in laboratory animals. Further studies are needed to prove all of these possible uses for barley.

After beer is brewed, the leftover barley (commonly known as brewer's spent grain) may be used for animal feed. It may also be allowed to sprout, producing a product called germinated barley foodstuff (GBF), which contains more protein than unsprouted barley. GBF also has high amounts of insoluble fiber. In several studies of humans, GBF has helped to relieve diarrhea, inflammation, pain, and other symptoms associated with gastrointestinal conditions such as ulcerative colitis.

Usually called barley grass, the leaves and leaf juice of the barley plant also appear to lower blood cholesterol levels. A small study conducted in China showed that taking barley grass decreased LDL in patients with type 2 diabetes. In addition, chemicals in barley grass may delay or prevent the development of blood vessel damage that can be caused by diabetes. It also contains large amounts of several B vitamins, beta carotene, folic acid, and calcium — making it a good source of nutrients.

When should I be careful taking it?

Individuals who have celiac disease should avoid barley seeds, cereals, and flour because they contain gluten. Barley grass is not believed to contain gluten, but individuals with any stomach or intestinal disease are advised to use it with caution and to stop taking it if problems develop.


A few cases have been reported of allergic reactions or asthma among individuals who were exposed to dust from processing barley seeds or grass.

Individuals with diabetes should watch their blood sugar levels carefully, if barley is eaten in significant amounts or if it is taken as a dietary supplement. Hypoglycemia (blood sugar that is too low) may occur. Symptoms of low blood sugar include shakiness, sweating, confusion, distorted speech, and loss of muscle control. If not corrected, low blood sugar can lead to unconsciousness and even death.

What side effects should I watch for?

No side effects have been reported from eating barley seeds, flour, or cereal or from taking barley grass juice or powder.

What interactions should I watch for?

In theory, taking fiber of the kind found in barley seed products could block the absorption of other substances that are taken at the same time. If you take barley seed products, do not take foods, drugs, or other dietary supplements within 2 hours.

Prescription Drugs

Due to a potential ability to lower blood sugar levels, large amounts of barley seed products may interfere with insulin and oral drugs for diabetes, such as:

  • Actos
  • Amaryl
  • Avandia
  • glipizide (Glucotrol XL)
  • glyburide (Glynase)
  • Glyset
  • metformin (Glucophage)
  • Prandin
  • Precose

Barley seeds contain a chemical known as hordenine, which may stimulate parts of the nervous system. If hordenine is taken with prescription drugs that also cause nervous system stimulation, the risk of side effects such as anxiety, dizziness, fast heart beat, headache, insomnia, nausea, and restlessness may increase. Prescription drugs that may interact with hordenine include:

  • Alpha blockers such as doxazosin and terazosin
  • Asthma drugs such as albuterol and metaproterenol
  • Beta blockers such as metoprolol and propranolol

Non-prescription Drugs

Non-prescription cough and cold remedies often contain pseudoephedrine (PSE) or phenylepherine, drugs which may increase the risk of side effects such as anxiety, dizziness, fast heart beat, headache, insomnia, nausea, and restlessness when they are taken with large amounts of barley seed products.

Herbal Products

Because barley seed products may decrease blood sugar levels, taking them with other blood sugar-lowering herbal products may result in hypoglycemia — blood sugar that is too low. Herbals that may reduce blood sugar include:

  • Eleuthero
  • Fenugreek
  • Ginger (in high amounts)
  • Kudzu
  • Panax ginseng

No interactions between barley grass and prescription drugs, non-prescription drugs, other herbal products, or foods have been reported. However, not all potential interactions may be known. If you experience unexpected effects while taking barley grass with a drug or another dietary supplement, stop taking the barley grass and discuss the effects with your doctor or pharmacist.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals.

Should I take it?

Both the leaves and the seeds of the barley plant have been used as food and medicine for humans. They are also used widely in animal feeds. For centuries, barley seeds (also called kernels or pearls) have been cooked as a grain similar to oats or rice. A source for the B vitamins, vitamin E, and folic acid, barley seeds are also ground into flour for baking or processed for use as a cereal. A sweetener known as malt sugar may be made from them and another barley derivative — malt extract — has been used as a laxative. In western countries, the main current use of barley is for making beer, but in other parts of the world, it is a primary grain for food. In Asia, barley seeds may be fermented and added to soybeans, salt, and seaweed to make one type of miso, a common flavoring agent for foods.

The leaves of barley plants are usually called barley grass because they are long and narrow like grass. During the first part of the 20th century, the juice of barley grass was discovered to be rich in vitamins and minerals. Barley grass is used as a food source in some parts of Asia and it is available for food supplementation as both a juice and a powder that can be added to foods or taken as capsules.

Dosage and Administration

No dosage recommendations are available in scientific literature for barley seeds or barley grass. When used as a food, barley appears to be safe even in large quantities.


Barley seeds are used for human and animal food. The fiber contained in barley may also have a lowering effect on blood sugar and blood cholesterol levels. While the leaves of the barley plant may also lower cholesterol, they are more often used as a nutritional supplement because they contain a relatively high amount of vitamins.


Because they contain gluten, barley seeds should be avoided by individuals with celiac disease.

Side Effects

No side effects have been attributed to the use of barley seeds or barley grass.


Due to a possible lowering of blood sugar, taking barley may increase the effects with drugs or herbs that also reduce blood sugar levels. It may increase the chance of anxiety and other nervous system side effects when it is taken with certain drugs for asthma and heart conditions. Because barley fiber may stay in the stomach, it may block the absorption of drugs and nutrients.


Anon: Barley. In: DerMarderosian A, Beutler JA, eds. Facts and Comparisons: The Review of Natural Products. St. Louis, MO, Facts and Comparisons. November 1994.

Anon: Barley grass. In: DerMarderosian A, Beutler JA, eds. Facts and Comparisons: The Review of Natural Products. St. Louis, MO, Facts and Comparisons. January 2002.

Armentia A, Rodriguez R, Callejo A, Martin-Esteban M, Martin-Santos JM, Salcedo G, Pascual C, et al. Allergy after ingestion or inhalation of cereals involves similar allergens in different ages. Clinical Experience in Allergy. 2002;32(8):1216-1222.

Bamba T, Kanauchi O, Andoh A, Fujiyama Y. A new prebiotic from germinated barley for nutraceutical treatment of ulcerative colitis. Journal of Gastroenterology and Hepatology. 2002;17(8):818-824.

Behall KM, Scholfield DJ, Hallfrisch J. Lipids significantly reduced by diets containing barley in moderately hypercholesterolemic men. Journal of the American College of Nutrition. 2004;23(1):55-62.

Bourdon I, Yokoyama W, Davis P, Hudson C, Backus R, Richter D, Knuckles B, Schneeman BO. Postprandial lipid, glucose, insulin, and cholecystokinin responses in men fed barley pasta enriched with beta-glucan. American Journal of Clinical Nutrition. 1999;69(1):55-63.

Burger WC, Qureshi AA, Din ZZ, Abuirmeileh N, Elson CE. Suppression of cholesterol biosynthesis by constituents of barley kernel. Atherosclerosis. 1984;51(1):75-87.

Delaney B, Nicolosi RJ, Wilson TA, Carlson T, Frazer S, Zheng GH, Hess R, et al. Beta-glucan fractions from barley and oats are similarly antiatherogenic in hypercholesterolemic Syrian golden hamsters. Journal of Nutrition. 2003;133(2):468-475.

Dongowski G, Huth M, Gebhardt E. Steroids in the intestinal tract of rats are affected by dietary-fibre-rich barley-based diets. British Journal of Nutrition. 2003;90(5):895-906.

Fukuda M, Kanauchi O, Araki Y, et al. Prebiotic treatment of experimental colitis with germinated barley foodstuff: a comparison with probiotic or antibiotic treatment. International Journal of Molecular Medicine. 2002;9(1):65-70.

Hanai H, Kanauchi O, Mitsuyama K, et al. Germinated barley foodstuff prolongs remission in patients with ulcerative colitis. International Journal of Molecular Medicine. 2004;13(5):643-647.

Ikegami S, Tomita M, Honda S, Yamaguchi M, Mizukawa R, Suzuki Y, Ishii K, et al. Effect of boiled barley-rice-feeding in hypercholesterolemic and normolipemic subjects. Plant Foods in Human Nutrition. 1996;49(4):317-328.

Jackson KA, Suter DA, Topping DL. Oat bran, barley and malted barley lower plasma cholesterol relative to wheat bran but differ in their effects on liver cholesterol in rats fed diets with and without cholesterol. Journal of Nutrition. 1994;124(9):1678-1684.

Jellin JM, Gregory P, Batz F, Hitchens K, et al, eds. Pharmacist's Letter/Prescriber's Letter. Natural Medicines Comprehensive Database, 3rd Edition. Stockton CA: Therapeutic Research Facility, 2000.

Jenkins DJ, Wolever TM, Jenkins AL. Starchy foods and glycemic index. Diabetes Care. 1988;11(2):149-159.

Kanauchi O, Mitsuyama K, Homma T, et al. Treatment of ulcerative colitis patients by long-term administration of germinated barley foodstuff: multi-center open trial. International Journal of Molecular Medicine. 2003;12(5):701-704.

Kanauchi O, Serizawa I, Araki Y, et al. Germinated barley foodstuff, a prebiotic product, ameliorates inflammation of colitis through modulation of the enteric environment. Journal of Gastroenterology. 2003;38(2):134-141.

Kanauchi O, Suga T, Tochihara M, et al. Treatment of ulcerative colitis by feeding with germinated barley foodstuff: first report of a multicenter open control trial. Journal of Gastroenterology. 2002;37(Suppl 14):67-72.

Keogh GF, Cooper GJ, Mulvey TB, et al. Randomized controlled crossover study of the effect of a highly beta-glucan-enriched barley on cardiovascular disease risk factors in mildly hypercholesterolemic men. American Journal of Clinical Nutrition. 2003;78(4):711-718.

Li J, Kaneko T, Qin LQ, Wang J, Wang Y, Sato A. Long-term effects of high dietary fiber intake on glucose tolerance and lipid metabolism in GK rats: comparison among barley, rice, and cornstarch. Metabolism. 2003;52(9):1206-1210.

Li J, Kaneko T, Qin LQ, Wang J, Wang Y. Effects of barley intake on glucose tolerance, lipid metabolism, and bowel function in women. Nutrition. 2003;19(11-12):926-929.

Liljeberg HG, Granfeldt YE, Bjorck IM. Products based on a high fiber barley genotype, but not on common barley or oats, lower postprandial glucose and insulin responses in healthy humans. Journal of Nutrition. 1996;126(2):458-466.

Lupton JR, Morin JL, Robinson MC. Barley bran flour accelerates gastrointestinal transit time. Journal of the American Dietetic Association. 1993 ;93(8):881-885.

Lupton JR, Robinson MC, Morin JL. Cholesterol-lowering effect of barley bran flour and oil. Journal of the American Dietetic Association. 1994;94(1):65-70.

Mahdi GS, Naismith DJ. Role of chromium in barley in modulating the symptoms of diabetes. Annals of Nutrition and Metabolism. 1991;35(2):65-70.

McIntosh GH, Whyte J, McArthur R, Nestel PJ. Barley and wheat foods: influence on plasma cholesterol concentrations in hypercholesterolemic men. American Journal of Clinical Nutrition. 1991;53(5):1205-1209.

Naismith DJ, Mahdi GS, Shakir NN. Therapeutic value of barley in the management of diabetes. Annals of Nutrition and Metabolism. 1991;35(2):61-64.

Peirce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: Stonesong Press; 1999.

Qureshi AA, Burger WC, Peterson DM, Elson CE. The structure of an inhibitor of cholesterol biosynthesis isolated from barley. Journal of Biological Chemistry. 1986;261(23):1544-1550.

Shukla K, Narain JP, Puri P, Gupta A, Bijlani RL, Mahapatra SC, Karmarkar MG. Glycaemic response to maize, bajra and barley. Indian Journal of Physiology and Pharmacology. 1991;35(4):249-254.

Truswell AS. Cereal grains and coronary heart disease. European Journal of Clinical Nutrition. 2002;56(1):1-14.

Wursch P, Pi-Sunyer FX. The role of viscous soluble fiber in the metabolic control of diabetes. A review with special emphasis on cereals rich in beta-glucan. Diabetes Care. 1997;20(11):1774-1780.

Yang JL, Kim YH, Lee HS, Lee MS, Moon YK. Barley beta-glucan lowers serum cholesterol based on the up-regulation of cholesterol 7alpha-hydroxylase activity and mRNA abundance in cholesterol-fed rats. Journal of Nutritional Science and Vitaminology (Tokyo). 2003;49(6):381-387.

Yu YM, Chang WC, Chang CT, Hsieh CL, Tsai CE. Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes. Diabetes Metabolism. 2002;28(2):107-114.

Zhang JX, Lundin E, Andersson H, et al. Brewer's spent grain, serum lipids and fecal sterol excretion in human subjects with ileostomies. Journal of Nutrition. 1991;121(6):778-784.

(Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.)

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