Ginkgo (Ginkgo biloba), also known as the maidenhair tree, is a gymnosperm. It’s considered a living fossil, since the genus Ginkgo has only one species. The name ginkgo means ‘silver apricot’ in Chinese. The tree is known to grow wild only in two small areas in China (1). Its importance lies in its curative capabilities.

Ginkgo tree

This deciduous tree is generally 20 to 35 meters tall, but can grow over 50 meters. It is deep rooted and resistant to wind and snow damage, and has an amazingly long life. Some specimens are more than 2,500 years old. Its wood is resistant to disease and insect. Its leaves resemble some of the pinnae of the maidenhair fern (Adiantum capillus-veneris) and hence the name maidenhair tree (1).

Effects of ginkgo

Ginkgo leaves contain medicinal properties. Its extract contains flavonoid glycosides and ginkgolides, which are used in pharmaceuticals. The leaf extract contain nootropic properties that boost human cognitive abilities. Therefore, it finds use as memory enhancer and anti-vertigo agent. Research has shown that ginkgo extract effect the human body in 3 ways (1):

a. They improve blood flow to tissues and organs, including microcirculation in small capillaries.

b. They act as an antioxidant by providing protection against oxidative cell damage.

c. They block the effects of platelet aggregation and blood clotting, thus preventing the development of cardiovascular, renal, respiratory and central nervous system disorders.

Medicinal uses of ginkgo

Ginkgo is one of the 10 best-selling herbal medications in the US, where it’s classified as a dietary supplement. No wonder you find ginkgo listed on the labels of every energy drink! Its leaf extract is the most widely sold phyto-medicine in Europe. There are no less than 120 published clinical studies on ginkgo. Gingko, in its various forms, is used for (2):

a. Treatment of early-stages of Alzheimer’s disease, vascular dementia, peripheral claudication and tinnitus.

b. Alleviating the symptoms of cerebrovascular disease and dementia.

c. Curing sexual dysfunction.

d. Alleviating mountain sickness.

e. Preventing macular degeneration, asthma and hypoxia.

f. Recommended for use in Raynaud’s disease, acrocyanosis, and post-phlebitic syndrome by the World Health Organization.

Dosage of ginkgo

The following dosage has been recommended for various ailments (1):

a. Patients of memory problems and dementia: 2 to 3 doses of 120 to 240 mg daily.

b. Patients of tinnitus and peripheral vascular disease: 2 to 3 doses of 160 mg per day.

This dosage is for adults and should not be given to children without consulting the physician, as the dosage varies from child to child.

To ascertain the effectiveness of ginkgo, an initial period of 6 to 12 weeks should be given. However, the results may become apparent as early as 4 weeks.

Adverse effects of ginkgo

An estimated 2 billion 120 mg daily doses of ginkgo have been sold in the last 20 years at the cost of approximately $15 to $20 each. Ginkgo is generally well tolerated, with side effects being rare and usually mild. However, the following adverse effects have been noticed (2):

a. Occurrence of nausea, vomiting, diarrhea, headaches, dizziness, palpitation, restlessness, weakness or skin rashes.

b. Inhibition of the platelet-activating factor. This requires discontinuing ginkgo between 36 hours and 14 days before surgery.

c. Increased risk of bleeding, if used with herbal medications, like feverfew, garlic, ginseng, dong quai, red clover and other natural coumarins.

d. Bleeding complications, including subdural hematoma, subarachnoid hemorrhage, intracerebral hemorrhage and hyphema.

e. Toxicity through use of unprocessed ginkgo leaf, as it contains toxic ginkgolic acids.

f. Adverse effect on pregnant women or those hypersensitive to ginkgo preparations.

g. Increased risk of bleeding, if used in combination with warfarin, antiplatelet agents, and certain other herbal medications.
h. Adverse effects on those taking monoamine oxidase inhibitors.

Despite these adverse effects, ginkgo offers a relatively safe, inexpensive and modestly effective treatment option for a string of diseases and conditions. However, its use should always be made under the recommendations and supervision of a physician.

References

1-http://en.wikipedia.org/wiki/Ginkgo
2-http://www.aafp.org/afp/20030901/923.html