Ginkgo Biloba

Description
Ginkgo Biloba is often refereed to as a "living fossil" because it is believed to be the world's oldest living species at about 200 million years old. The Ginkgo tree has been used in Traditional Chinese Medicine for over 4,000 years. Various parts of the Ginkgo tree were reportedly used in the treatment of respiratory ailments, to improve circulation, as a digestive aid, as a tonic for memory loss in the elderly and as a longevity elixir. In Germany, Ginkgo is a top-selling over- the-counter and prescription drug. Modern Ginkgo Biloba extracts are produced from the leaves of cultivated trees and still enjoy a large audience for the treatment of various disorders. High quality Ginkgo biloba extract is normally standardized to 24% ginkgo flavone glycosides and 6% terpene lactones.

Claims

• Improves memory / mental sharpness
• Alleviates symptoms of Alzheimer's disease
• Anti-depressant
• Improves circulation
• Thins blood/cardiovascular health
• Antioxidant

Theory
The two groups of phytochemicals to which ginkgo biloba is normally standardized, ginkgo flavone glycosides and terpene lactones, are considered to be the primary active constituents. The flavone glycosides, which include quercetin, kaempherol and isorhamnetin, are responsible for the antioxidant properties of ginkgo biloba extract. The terpene lactones, which include ginkgolides A, B and C, as well as bilobalide, possess several activities. These activities include neuroprotection, improvement of choline (a neurotransmitter) uptake in brain synapses and inhibition of platelet activating factor (which reduces the tendency of the blood to clot).

Scientific Support
A wide variety of clinical studies have been conducted on the benefits of Ginkgo biloba extract, many in Germany, but several in the USA. Major findings include:

• Oxygen use (improvement of hypoxic (lack of oxygen) tolerance)
• Brain circulation (inhibition / prevention of brain damage due to trauma and/or toxicity)
• Eye health (protection of retina)
• Neurotransmitter support (inhibits age-related loss of choline receptors and stimulates choline uptake in the hippocampus region of the brain)
• Memory support (increased memory performance and learning capacity)
• Systemic circulation (improvement of blood flow, particularly in microcirculation of capillaries)
• Cardiovascular risk factor reduction (antioxidant effects, reduces activity of platelet activating factor – reduces tendency of blood to clot)
• General neuroprotective effects

A meta-analysis, published in the British Journal of Pharmacology, analyzed the quality of research conducted in over 40 clinical studies investigating Ginkgo biloba extract in the treatment of cerebral insufficiency. Cerebral insufficiency is associated with age-related mental decline or dementia. The resulting analysis concluded that the reviewed research was on par with research conducted on traditional prescription medications for treatment of dementia (including Alzheimer's) and that Ginkgo biloba extract is effective in reducing all symptoms of cerebral insufficiency, including impaired mental function. In a placebo-controlled, double-blind, randomized study, 72 patients with cerebral insufficiency (lack of blood flow to the brain) were subjected to a computerized test of short term memory. At the end of six weeks, the group receiving Ginkgo biloba extract exhibited a statistically significant improvement in short term memory capacity while the placebo group showed no significant increase. Clinical evidence indicates that Ginkgo biloba extract may be useful in the treatment of certain types of depression, notably "resistant" depression. At least one study correlated a reduction of cerebral blood flow in depressed patients. In one placebo-controlled study, patients who continued to exhibit symptoms of depression after the use of antidepressants were given 240 mg per day of Ginkgo biloba extract. The patients receiving Ginkgo biloba extract experienced a significant reduction in depressive symptoms as well as an improvement in cognitive function. In an open clinical trial of 60 patients having erectile dysfunction, 60mg of ginkgo per day, 50% of the patients regained potency and 25% showed improved arterial blood flow following 6 months of supplementation (5% showed no improvement)

There has been some question as to the ability of Ginkgo biloba extract to improve cognitive function in healthy subjects (which is very difficult to measure). However, two recent studies of healthy volunteers measured brain activity using sensitive electroencephalography (EEG) and found that dosages of 120-240mg of Ginkgo biloba extract increase cognitive function (measured as alpha wave activity) within 30 minutes (peak measures were recorded 2-3 hours after consuming the supplements). The enhancement in alpha wave activity was similar to that achieved through the use of drugs that improve cognitive function. Both studies concluded that Ginkgo biloba extract improves cognitive function in healthy subjects.

Safety
Ginkgo Biloba extract is, very rarely, associated with gastrointestinal upset, allergic skin reaction and headache. There are no known contraindications or interactions with other drugs. Ginkgo Biloba is not known to be toxic at high dosages although its inhibition of platelet activating factor could pose a concern to those individuals with blood clotting problems or those taking anticoagulant medications (so check with your doctor before taking Ginkgo Biloba).

Value
Ginkgo Biloba is valuable for a broad array of health concerns related to problems with microcirculation, whether their locus is in the brain, legs or sex organs. This quality has made it a key ingredient in natural remedies for erectile dysfunction. Ginkgo Biloba's neuroprotective effects are also well established and its benefits in improving mental function and memory in healthy subjects look promising.

Dosage
The general consensus is that for the treatment of microcirculation problems in the extremities, including vertigo, tinnitus and intermittent claudication, a dosage of 120-160 mg per day is suitable. For treatment of dementia, mild depression, and improvement of cognitive abilities, higher doses (about 240 mg/day) are recommended. For best results, daily dosage is typically split into 2-3 separate doses. In treatments for erectile dysfunction, be sure to look for an extract standardized to at least 24% ginkgo flavone glycosides and 6% terpene lactones, since this is the type of extract that has been shown to be effective in virtually every clinical trial.