Barley is considered to be the first cereal grain cultivated by humans. Since biblical times, ancient Asian and Middle Eastern cultures reportedly included young wheat and barley grass plants in their diets. Historically, the plant species was used in the treatment of skin, liver, blood, and GI disorders. Ancient Greeks used the mucilage derived from the cereal to treat GI inflammations. Gladiators ate barley for strength and stamina.
The juice of barley grass contains beta carotene, vitamins B1, B2, B6, B12, pantothenic acid, and folic acid. Minerals present include potassium, calcium, iron, phosphorus, and magnesium. Other constituents are chlorophyll, amino acids, protein, fiber, and enzymes. Cobalamin or vitamin B12 deficiency may be avoided in vegetarian diets by supplementation with dehydrated barley grass juice.