Olive leaf is the leaf of the

olive The olive, botanical name ''Olea europaea'', meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as ''Olea europaea'' ...

tree (''Olea europaea''). Although

olive oil Olive oil is a liquid fat obtained from olives (the fruit of ''Olea europaea''; family Oleaceae), a traditional tree crop of the Mediterranean Basin, produced by pressing whole olives and extracting the oil. It is commonly used in cooking: f ...

is well known for its flavor and possible health benefits, the leaf and its

extract An extract is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures, absolutes or in powder form. The aromatic principles of many spices, nuts, h ...

s remain under preliminary research with unknown effects on human health.

Leaf characteristics

The silvery green leaves are oblong, measuring long and wide. When consumed, leaves have an astringent bitter taste.

Chemical compounds

Olive phenolics are much more concentrated in the leaves compared with olive fruit or olive oil: 1450 mg total phenolics/100 g fresh leaf vs. 110 mg/100 g fruit and 23 mg/100 ml extra virgin olive oil. Chemical compounds in unprocessed olive leaf are

oleuropein Oleuropein is a glycosylated seco-iridoid, a type of phenolic bitter compound found in green olive skin, flesh, seeds, and leaves. The term oleuropein is derived from the botanical name of the olive tree, ''Olea europaea''. Because of its bitter ...

and

hydroxytyrosol Hydroxytyrosol is an organic compound with the formula . Classified as a phenylethanoid, i.e. a relative of phenethyl alcohol, Its derivatives are found in a variety of natural sources, notably olive oils and wines. The compound is colorless solid ...

, as well as

polyphenol Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of ...

s and

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s, including

luteolin Luteolin is a flavone, a type of flavonoid, with a yellow crystalline appearance. Luteolin is the principal yellow dye compound that is obtained from the plant '' Reseda luteola'', which has been used as a source of the dye since at least the f ...

rutin Rutin, also called rutoside, quercetin-3-O-rutinoside and sophorin, is the glycoside combining the flavonol quercetin and the disaccharide rutinose (α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranose). It is a flavonoid found in a wide variety of pla ...

caffeic acid Caffeic acid is an organic compound that is classified as a hydroxycinnamic acid. This yellow solid consists of both phenolic and acrylic functional groups. It is found in all plants because it is an intermediate in the biosynthesis of lignin, one ...

catechin Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic ...

and

apigenin Apigenin (4′,5,7-trihydroxyflavone), found in many plants, is a natural product belonging to the flavone class that is the aglycone of several naturally occurring glycosides. It is a yellow crystalline solid that has been used to dye wool. S ...

Elenolic acid Elenolic acid is a component of olive oil, olive infusion and olive leaf extract. It can be considered as a marker for maturation of olives. Oleuropein, a chemical compound found in olive leaf from the olive tree, together with other closely r ...

is a component of olive oil and olive leaf extract. It can be considered as a marker for maturation of olives. Oleuropein, together with other closely related compounds such as 10-hydroxyoleuropein,

ligstroside Ligstroside is an important phenolic compound present in olive cultivars. It has a role as a plant metabolite and an antineoplastic agent. Differs from oleuropein by one hydroxyl group In chemistry, a hydroxy or hydroxyl group is a funct ...

and 10-hydroxyligstroside, are

tyrosol Tyrosol is an organic compound with the formula . Classified as a phenylethanoid, i.e. a derivative of phenethyl alcohol, It is found in a variety of natural sources. The compound is colorless solid. The principal source in the human diet is ol ...

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

s of elenolic acid. The phenolic composition of olive leaf extract varies according to plant variety, harvesting season and method, leaf maturity, storage conditions and extraction method.

Culinary uses

Olive leaves are sometimes used in deluxe

Chinese cuisine Chinese cuisine encompasses the numerous cuisines originating from China, as well as overseas cuisines created by the Chinese diaspora. Because of the Chinese diaspora and historical power of the country, Chinese cuisine has influenced many ot ...

. Olive leaves have been used by

Gina Keatley Gina Keatley (born March 9, 1980) is an American nutritionist, media personality, and television host. She is better known for her food-focused television shows and her approach to health and weight loss. Gina was awarded ''The President’s Coun ...

in the creation of Matche, powdered olive leaves used on desserts and in tea.

Historical uses

Historically the benefits of olive leaves have been used in

traditional medicine Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...

practices as folk remedies for the treatment of various illnesses. Studies suggest that olive leaf extract could help balance blood sugar in type 2 diabetes patients. However, scientific evidence for health effects of using olive leaf extract has been deemed insufficient by the

European Food Safety Authority The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002, ...

to prove any cause-and-effect relationship.

References

{{Olives Olives Medicinal plants Leaves