Ginkgo Biloba

Ginkgo biloba is the world’s longest living species of tree; individual trees live as long as 1,000 years. Ginkgo grows most prominently in the southern and eastern US and in China. The leaves of the tree are used.

Medicinal use of ginkgo can be traced back almost 5,000 years in Chinese herbal medicine. The nuts of the tree were most commonly recommended and used to treat respiratory tract ailments. A tea of the leaves was occasionally used for elderly persons experiencing memory loss.

Active constituents of Ginkgo Biloba

The medical benefits of Ginkgo biloba  rely primarily on two groups of active components: the ginkgo flavone glycosides and the terpene lactones. The 24% ginkgo flavone glycoside designation on Ginkgo biloba labels indicates the carefully measured balance of bioflavonoids. These bioflavonoids are primarily responsible for Ginkgo biloba’s antioxidant activity and ability to inhibit platelet aggregation (stickiness). These two actions may help Ginkgo biloba prevent circulatory diseases such as atherosclerosis and support the brain and central nervous system.

The unique terpene lactone components found in Ginkgo biloba, known as ginkgolides and bilobalide typically make up 6% of the extract. They are associated with increased circulation to the brain and other parts of the body as well as exert a protective action on nerve cells. Ginkgolides may improve circulation and inhibit platelet-activating factor (PAF). Bilobalide protects the cells of the nervous system. Recent animal studies indicate that bilobalide may help regenerate damaged nerve cells.

Circulatory actions of Ginkgo Biloba

Ginkgo biloba increases circulation to both the brain and extremities of the body. In addition to inhibiting platelet stickiness, Ginkgo biloba regulates the tone and elasticity of blood vessels. In other words, it makes circulation more efficient. This improvement in circulation efficiency extends to both large vessels (arteries) and smaller vessels (capillaries) in the circulatory system.

Cognitive function of Ginkgo Biloba

Recently, the ginkgo extract EGb 761 was found to increase alpha wave and decrease theta wave activity following oral intakes of 120 or 240 mg in healthy volunteers.6 These brain wave changes indicate that EGb 761 is capable of improving cognitive function as demonstrated in increased mental sharpness, concentration, and memory. Three double blind studies have now shown that Ginkgo biloba is helpful for persons in early stages of Alzheimer’s disease, as well as the closely related multi-infarct dementia. Patients with other types of dementia also respond to Ginkgo biloba, including, as mentioned above, problems due to poor blood flow to the brain.

Antioxidant properties of Ginkgo Biloba

Ginkgo biloba has antioxidant actions in the brain, retina of the eye, and the cardiovascular system. One double blind study found that  of Ginkgo biloba could help people with macular degeneration, an oxidation-related disorder causing decreased or lost vision. Diabetic retinopathy is also improved by Ginkgo biloba, according to a double blind study. Its antioxidant activity in the brain and central nervous system may help prevent age-related declines in brain function. Ginkgo biloba’s antioxidant activity in the brain is of particular interest. The brain and central nervous system are particularly susceptible to free radical attack. Free radical damage in the brain is widely accepted as being a contributing factor in many disorders associated with aging, including Alzheimer’s disease.

Antidepressant action of Ginkgo Biloba

One double blind study in Germany found that elderly depressed people with mild dementia (who were not responding to antidepressant medications) responded well to Ginkgo biloba supplements.

Nerve protection and PAF inhibition

One of the primary protective actions of the ginkgolides is their ability to inhibit a substance known as platelet-activating factor (PAF). PAF is a mediator released from cells that causes platelets to aggregate (clump together). High amounts of PAF are associated with damage to nerve cells, poor blood flow to the central nervous system, inflammatory conditions, and bronchial constriction. Much like free radicals, higher PAF levels are also associated with aging. Ginkgolides and bilobalide protect nerve cells in the central nervous system from damage during periods of ischemia (lack of oxygen to tissues in the body). This action may be supportive for persons who have suffered a stroke.

Tinnitus and balance

Ginkgo may improve tinnitus (ringing in the ears) and balance problems related to the inner ear, an important part of maintaining balance. Double blind studies have confirmed the benefit of Ginkgo biloba for people with tinnitus or vertigo.

How much  of Ginkgo Biloba is usually taken?

Ginkgo biloba, standardized to contain 6% terpene lactones and 24% flavone glycosides, can be taken in the amount of 120–160 mg per day. Relatively high (240 mg per day) amounts have been used in reports studying people with age-associated memory loss, mild cognitive impairment, mild to moderate Alzheimer’s disease, and resistant depression. Ginkgo biloba may need to be taken for six to eight weeks before desired actions are noticed. Although non-standardized leaf and tinctures are available, there is no well-established dosage for these forms.