Scientific Name(s): Hordeum vulgare L., Hordeum
distichon L. Family: Poaceae (grasses)
Common Name(s): Barley grass
Uses
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.
Dosing
A dose of 15 g/day
dried barley leaf extract has been used to lower cholesterol.
Contraindications
None identified.
Pregnancy/Lactation
Information regarding
safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
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.
Toxicology
No data.
Botany
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. 1 At
this stage of development, the young grass contains vitamins and minerals
similar to those of dark green vegetables. 2 Barley
grass is available commercially in dried and powdered form prepared from the
whole leaves or juice obtained by milling the leaves.
History
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. 3 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. 3
Chemistry
A wide spectrum of
vitamins, minerals, amino acids, and enzymes have been isolated from barley
grass. 2 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. 3 , 4 A
number of C-glycosylflavones with documented antioxidant effects have been
isolated from the plant; saponarin is the major flavone. 5
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. 6 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. 7 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. 1 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 6 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. 8
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. 1 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. 9
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. 1
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. 8 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. 6 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. 10In
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. 11
Dosage
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. 6
Pregnancy/Lactation
Information regarding
safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
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.
Toxicology
Research reveals
little or no information regarding toxicology with the use of this product.
Bibliography
1. Yu
YM, Wu CH, Tseng CE, Tsai CE, Chang WC. Antioxidative and hypolipidemic effects
of barley leaf essence in a rabbit model of atherosclerosis. Jpn J Pharmacol .
2002;89:142-148.
2. Barley Grass. Available online at: http://www.naturaltechniques.com/barley_green_grass.htm . Accessed March 7, 2005.
3. Margen S. The Wellness Encyclopedia of Food and Nutrition . New York, NY: Rebas; 1992.
4. Balch JF, Balch PA. Prescription for Nutritional Healing . 2nd ed. Garden City Park, NY: Avery Publishing Group; 1997.
5. Ohkawa M, et al. Three new anti-oxidative saponarin analogs from young green barley leaves. Chem Pharm Biol . 1998;46:1887-1890.
6. Yu YM, Chang WC, Liu CS, Tsai CM. Effect of young barley leaf extract and adlay on plasma lipids and LDL oxidation in hyperlipidemic smokers. Biol Pharm Bull . 2004;27:802-805.
7. Ohtake H, Nonaka S, Sawada Y, Hagiwara Y, Hagiwara H, Kubota K. Studies on the constituents of green juice from young barley leaves. Effect on dietarily induced hypercholesterolemia in rats [in Japanese]. Yakugaku Zasshi . 1985;105:1052-1057.
8. 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 Metab . 2002;28:1262.
9. Cremer L, Herold A, Avram D, Szegli G. A purified green barley extract with modulatory properties upon TNF alpha and ROS released by human specialized cells isolated from RA patients. Roum Arch Microbiol Immunol . 1998;57:231-242.
10. Chernomorsky S, Segelman A, Poretz RD. Effect of dietary chlorophyll derivatives on mutagenesis and tumor cell growth. Teratog Carcinog Mutagen . 1999;19:313-322.
11. Donaldson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab . 2000;44:229-334.
2. Barley Grass. Available online at: http://www.naturaltechniques.com/barley_green_grass.htm . Accessed March 7, 2005.
3. Margen S. The Wellness Encyclopedia of Food and Nutrition . New York, NY: Rebas; 1992.
4. Balch JF, Balch PA. Prescription for Nutritional Healing . 2nd ed. Garden City Park, NY: Avery Publishing Group; 1997.
5. Ohkawa M, et al. Three new anti-oxidative saponarin analogs from young green barley leaves. Chem Pharm Biol . 1998;46:1887-1890.
6. Yu YM, Chang WC, Liu CS, Tsai CM. Effect of young barley leaf extract and adlay on plasma lipids and LDL oxidation in hyperlipidemic smokers. Biol Pharm Bull . 2004;27:802-805.
7. Ohtake H, Nonaka S, Sawada Y, Hagiwara Y, Hagiwara H, Kubota K. Studies on the constituents of green juice from young barley leaves. Effect on dietarily induced hypercholesterolemia in rats [in Japanese]. Yakugaku Zasshi . 1985;105:1052-1057.
8. 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 Metab . 2002;28:1262.
9. Cremer L, Herold A, Avram D, Szegli G. A purified green barley extract with modulatory properties upon TNF alpha and ROS released by human specialized cells isolated from RA patients. Roum Arch Microbiol Immunol . 1998;57:231-242.
10. Chernomorsky S, Segelman A, Poretz RD. Effect of dietary chlorophyll derivatives on mutagenesis and tumor cell growth. Teratog Carcinog Mutagen . 1999;19:313-322.
11. Donaldson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab . 2000;44:229-334.
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