Ginkgo biloba

Pronunciation
Scientific names: Ginkgo biloba L.

Common names: Ginkgo, maidenhair tree, kew tree, ginkyo, yinhsing Japanese silver apricot

Efficacy-safety rating:

ÒÒ...Ethno or other evidence of efficacy.

Safety rating:

...Little exposure or very minor concerns.

What is Ginkgo biloba?

The ginkgo is the world's oldest living tree species; it can be traced back more than 200 million years to the fossils of the Permian geologic period and is the sole survivor of the family Ginkgoaceae. Individual trees may live as long as 1,000 years and grow to a height of approximately 38 m. Ginkgo has characteristic fan-shaped leaves. Male trees more than 20 years old blossom in the spring. Adult female trees produce a plum-like, gray-tan fruit that falls in late autumn. Its fleshy pulp has a foul, offensive odor and causes skin reactions. The edible inner seed resembles an almond and is sold in Asian markets.

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What is it used for?

Traditional/Ethnobotanical uses

The ginkgo species almost became extinct during the last ice age that began approximately 2 million years ago. The species survived in China, where it has been cultivated as a sacred tree and still is found decorating Buddhist temples throughout Asia. Preparations have been used for medicinal purposes for more than a thousand years. Traditional Chinese physicians used ginkgo leaves to treat asthma and chilblains (inflammation of the small blood vessels in the skin in response to cold, but above freezing, temperatures). Ancient Chinese and Japanese people ate roasted ginkgo seeds and considered them a digestive aid and preventive for drunkenness. In the Western world, ginkgo has only been used since the 1960s. Ginkgo is one of the most commonly prescribed medications in Europe, but is not approved for medical use in the United States where it is sold only as a nutritional supplement.

General uses

Ginkgo has been studied extensively in differing medical conditions. Evidence is lacking to support a protective role in heart/blood vessel conditions and stroke, and a definitive place in therapy for dementia and schizophrenia, although promising, is yet to be established. The findings from 2 large trials are important in evaluating the efficacy of G. biloba extracts.

What is the recommended dosage?

Standardized ginkgo leaf extracts such as EGb 761 (Tebonin forte, Schwabe) have been used in clinical trials for mental and circulatory disorders at daily doses of 120 to 240 mg of extract.

How safe is it?

Contraindications

Absolute contraindications have not been established.

Pregnancy/nursing

Evidence is lacking on the safety of ginkgo; preparations should not be used during pregnancy and lactation.

Interactions

Ginkgo may affect the metabolism of various drugs. Case reports of various interactions exist; however, consistent data are limited.

Side Effects

Severe adverse reactions are rare; possible reactions include headache, dizziness, heart palpitations, and GI and skin reactions. Ginkgo pollen can be strongly allergenic. Contact with the fleshy fruit pulp may cause an allergic skin reaction similar to poison ivy.

Toxicities

A toxic syndrome has been recognized in Asian children who have ingested ginkgo seeds.

References

  1. Ginkgo. Review of Natural Products. Facts & Comparisons [database online]. St. Louis, MO: Wolters Kluwer Health Inc; August 2011.

Copyright © 2009 Wolters Kluwer Health

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