Scientific Name(s): Hordeum distichon L., Hordeum vulgare L.
Common Name(s): Barley grass
Medically reviewed by Drugs.com. Last updated on Apr 1, 2019.
Barley grass is rich in vitamins and minerals, has antioxidant properties, and has been shown to reduce cholesterol levels. Use as a cancer preventive or treatment has been suggested; however, this remains to be substantiated. (See also Barley monograph.)
A dose of 15 g/day dried barley leaf extract has been used to lower cholesterol.
Information regarding safety and efficacy in pregnancy and lactation is lacking.
None well documented.
Although hypersensitivity to barley products typically is associated with the seed and not the green leaves or shoots, patients with celiac disease or other sensitivities to barley probably should avoid use of barley grass.
- Poaceae (grass)
Barley grass consists of the young green leaves of the barley plant, as opposed to the grain (for barley grain, refer to the Barley monograph). Barley plants can grow under a wide range of soil and climatic conditions. However, superior soil conditions are reflected in plants with higher nutritional content, and commercial suppliers of barley grass strive for optimal soil conditions for the crop. Favorable results have been achieved with crops grown in California. Barley grass is at its nutritional peak before the plant begins to produce flowers and seeds; harvesting takes place approximately 2 weeks after seeding. At this stage of development, the young grass contains vitamins and minerals similar to those of dark green vegetables. Barley grass is available commercially in dried and powdered form prepared from the whole leaves or juice obtained by milling the leaves.Lahouar 2015, USDA 2017
Barley is considered to be the first cereal grain cultivated by humans. Ancient Asian and Middle Eastern cultures reportedly included young wheat and barley grass plants in their diets.Margen 1992 In the early part of the 20th century, the roles of cereal grains and vitamins in nutrition were investigated. For example, chickens fed a 10% mixture of cereal grass responded well in growth, appeared to have increased resistance to degenerative diseases, and increased winter egg production. Further studies concerning "grass juice factor," a water-soluble extract of grass juice, found several beneficial growth and health effects from its supplementation in animal diets. A dehydrated preparation of cereal grass called cerophyl was approved as an "accepted food" by the Council of Foods of the American Medical Association in 1939.Lahouar 2015, Margen 1992
A wide spectrum of vitamins, minerals, amino acids, and enzymes have been isolated from barley grass. It is particularly rich in beta-carotene, calcium, iron, and vitamin C, and contains abundant chlorophyll. Other vitamins, electrolytes (eg, potassium, phosphorus, magnesium), and minerals isolated from the plant in substantial quantities include vitamins B1, B2, B6, B12, pantothenic acid, and folic acid. Also of note are enzymes, particularly the antioxidant enzyme superoxide dismutase, and nitrogen reductase.Balch 1997, Margen 1992 A number of C-glycosylflavones with documented antioxidant effects have been isolated from the plant; saponarin is the major flavone.Duke 2017, Ohkawa 1998
Uses and Pharmacology
Many claims have been made regarding the health benefits of barley grass supplements. Suggested benefits include prevention and cure of cancer, treatment of HIV infection, cholesterol lowering, detoxification of pollutants, protection against solar and other forms of radiation, and boosting energy and immunity. However, objective evidence supporting many of these claims is lacking.
Cholesterol-lowering effects have been attributed to the hexacosyl alcohol and beta-sitosterol fractions of barley leaf extract.Yu 2004 beta-sitosterol is thought to act by inhibiting the intestinal absorption of cholesterol and accelerating its catabolism to bile acid. The mechanism of action of hexacosyl alcohol remains unclear.
In hypercholesterolemic rats, beta-sitosterol decreased plasma cholesterol within 1 week.Ohtake 1985 Rabbits receiving a barley leaf supplement in combination with an atherogenic diet demonstrated reductions in plasma levels of serum triacylglycerol, total cholesterol, and low-density lipoprotein (LDL) cholesterol compared with animals on the atherogenic diet alone.Yu 2002 Histological examination of the thoracic aorta of these rabbits supported the findings; atherosclerotic lesions covered 90% of the surface in animals fed only the atherogenic diet compared with 60% in animals receiving barley leaf extract plus an atherogenic diet. However, the effect of probucol, an established hypocholesterolemic agent, was superior to that of barley leaves (8% lesions). This result indicates that, while barley leaf may be useful in the prevention of cardiovascular disease or as an adjuvant to other treatments, it unlikely is suitable as a primary treatment for atherosclerosis.
Decreases in plasma total cholesterol and LDL-C concentrations were observed in hypercholesterolemic men receiving 15 g/day barley leaf extractYu 2004 and high-density lipoprotein cholesterol (HDL-C) concentrations were increased. Barley leaf was most effective in patients with higher initial cholesterol levels. Similar results were reported in men with type 2 diabetes mellitus.Yu 2002
Reactive oxygen species have been shown to play an important part in mediating the production of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) and can be instrumental in the pathogenesis of diseases such as rheumatoid synovitis, arthritis, and gout. The ability of barley leaf extract to scavenge free radicals is thought to derive from the presence of polyphenolic compounds; free radicals are rendered less reactive by donation of hydrogen ions from the phenolic moiety with the formation of less reactive phenoxyl radicals.Yu 2002 Green barley extracts, in particular a purified extract containing substances less than 1 kDa, have shown in vitro inhibitory actions on TNF-α isolated from blood and spinal fluid of patients with rheumatoid arthritis.Cremer 1998
Increased production of oxygen-free radicals by peripheral blood leukocytes has been observed in rabbits receiving a high cholesterol diet; addition of barley leaf extract to the diet lowered their production.Lahouar 2015, Yu 2002
Blood levels of oxygen-free radicals were reduced by supplementation with 15 g/day barley leaf extract in patients with type 2 diabetes mellitus.Lahouar 2015, Yu 2002 Lahouar) Addition of vitamins C and E to the barley leaf supplements inhibited oxidation of small, dense LDL more effectively than barley leaf extract supplements alone. The lag phase of LDL oxidation was increased after supplementation with barley leaf extract. Similar results were noted in nondiabetic, hyperlipidemic subjects.Yu 2004 Antioxidative effects were less pronounced in smokers than in nonsmokers.
Barley grass extracts protect human fibroblasts against carcinogens. The mechanism of action is unknown but may be associated with the plant's antioxidant activity or its chlorophyll content. The antimutagenic effects of chlorophyll and its metabolites have been demonstrated in vitro and in vivo; it has been suggested that complexes may be formed between the carcinogen and the chlorophyll that may inactivate the carcinogen.Chernomorsky 1999 In addition, antioxidants, including superoxide dismutase, found in high concentrations in green barley juice protect against radiation and free radicals.Lahouar 2015
Animals receiving diets that include wheat grass have shown decreased cancer incidence; similar results might be expected with barley grass supplementation.
Research reveals no clinical data regarding the use of barley grass for cancer-preventive properties.
A dose of 15 g/day dried barley leaf extract has been used for cholesterol lowering. This dosage provided 40 to 45 mg total phenols, 3,500 to 4,000 units beta-carotene, and 15 to 20 mg vitamin C.Yu 2004
Pregnancy / Lactation
Information regarding safety and efficacy in pregnancy and lactation is lacking.
None well documented.
Hypersensitivity reactions to barley are well documented. These typically are attributed to the storage protein present in the seed of the plant and not to the green, aerial parts of the plant (see Barley monograph for further details). It may be prudent to restrict the use of barley grass in hypersensitive people, including those with celiac disease.
Research reveals little or no information regarding toxicology with the use of this product.
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