Olive leaf is the leaf of the

olive The olive, botanical name ''Olea europaea'' ("European olive"), is a species of Subtropics, subtropical evergreen tree in the Family (biology), family Oleaceae. Originating in Anatolia, Asia Minor, it is abundant throughout the Mediterranean ...

tree (''Olea europaea''). Although

olive oil Olive oil is a vegetable oil obtained by pressing whole olives (the fruit of ''Olea europaea'', a traditional Tree fruit, tree crop of the Mediterranean Basin) and extracting the oil. It is commonly used in cooking for frying foods, as a cond ...

extracted from the fruit of the tree is well known for its flavor and possible health benefits, the leaf and its

extract An extract (essence) 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 or absolutes or dried and powdered. The aromatic principles of ma ...

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 oil or olive fruit: 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 glycosylation, glycosylated seco-iridoid, a type of polyphenol, 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 ...

and

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

, as well as

polyphenol Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...

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 main yellow dye from the '' Reseda luteola'' plant, used for dyeing since at least the first millennium B.C. Luteolin was first isolated in pure f ...

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

caffeic acid Caffeic acid is an organic compound with the formula . It is a polyphenol with a key role in scavenging reactive oxygen species (ROS) generated in energy metabolism. Caffeic acid is also one major polyphenol responsible for maintaining normal le ...

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 flavone compound that is the aglycone of several naturally occurring glycosides. It is a yellow crystalline solid that has been used to dye wool. Apigenin is abundant in parsl ...

Elenolic acid Elenolic acid is a component of olive oil and olive leaf extract. It can be considered as a marker for maturation of olives. It is a subunit of oleuropein, a bitter chemical compound found in olives and the leaves of the olive tree, alongside c ...

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 Oleuropein is a glycosylation, glycosylated seco-iridoid, a type of polyphen ...

and 10-hydroxyligstroside, are

tyrosol Tyrosol is an organic compound with the formula . Classified as a phenylethanoid, 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 olive oi ...

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

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 comprises cuisines originating from Greater China, China, as well as from Overseas Chinese, Chinese people from other parts of the world. Because of the Chinese diaspora and the historical power of the country, Chinese cuisine ...

. Olive leaves have been used by

Gina Keatley Gina Keatley (born March 9, 1980) is an American nutritionist, Celebrity, media personality, and television host. She is better known for her food-focused television shows and her approach to health and weight loss. Keatley was awarded the Presid ...

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

Research

Scientific evidence for the supposed health effect of using olive leaf extract to manage

blood glucose The blood sugar level, blood sugar concentration, blood glucose level, or glycemia is the measure of glucose concentrated in the blood. The body tightly blood sugar regulation, regulates blood glucose levels as a part of metabolic homeostasis ...

levels 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 have any cause-and-effect relationship.

References

{{Olives

leaf A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leav ...

Medicinal plants Leaves