Scientific Name(s): Hordeum vulgare L., Hordeum distichon L. Family: Poaceae (grasses)
Common Name(s): Barley grass
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.
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.
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.
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. 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.
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 B 1 , B 2 , B 6 , B 12 , pantothenic acid, and folic acid. Also of note are enzymes, particularly the antioxidant enzyme superoxide dismutase, and nitrogen reductase. , A number of C-glycosylflavones with documented antioxidant effects have been isolated from the plant; saponarin is the major flavone.
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.Hyperlipidemia
Cholesterol-lowering effects have been attributed to the hexacosyl alcohol and β-sitosterol fractions of barley leaf extract. β-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.Animal data
In hypercholesterolemic rats, β-sitosterol decreased plasma cholesterol within 1 week. 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. 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.Clinical data
Decreases in plasma total cholesterol and LDL-C concentrations were observed in hypercholesterolemic men receiving 15 g/day barley leaf extract 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.Antioxidant activity
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-α) 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. 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.Animal data
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.Clinical data
Blood levels of oxygen-free radicals were reduced by supplementation with 15 g/day barley leaf extract in patients with type 2 diabetes mellitus. 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. Antioxidative effects were less pronounced in smokers than in nonsmokers.Cancer prevention
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. In addition, antioxidants, including superoxide dismutase, found in high concentrations in green barley juice protect against radiation and free radicals.Animal data
Animals receiving diets that include wheat grass have shown decreased cancer incidence; similar results might be expected with barley grass supplementation.Clinical data
Research reveals no clinical data regarding the use of barley grass for cancer-preventive properties.Other uses
In an observational study, patients reported improvement in fibromyalgia syndrome from a dietary intervention that included barley grass.
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 β-carotene, and 15 to 20 mg vitamin C.
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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