May 7, 2005
Q: What is Ginko Biloba and what is it good for? - Layperson
A: Ginkgo biloba is one of the most unique trees on the planet today. This fascinating tree is dioecious: male and female flowers grow on different trees. The Ginkgo hasn't been found growing in the wild but it has been preserved as a sacred tree in Chinese temple gardens since ancient times. The Ginkgo tree is also called the Maidenhair Tree because its leaves closely resemble those of the Maidenhair Fern.Ginkgo biloba is one of the most unique trees on the planet today. This fascinating tree is dioecious: male and female flowers grow on different trees. The Ginkgo hasn't been found growing in the wild but it has been preserved as a sacred tree in Chinese temple gardens since ancient times.
The Ginkgo tree is also called the Maidenhair Tree because its leaves closely resemble those of the Maidenhair Fern. The first mentioned use of Ginkgo biloba appears in China. Ginkgo leaf is first mentioned in Lan Mao's Dian Nan Ben Cao, published in 1436 during the Ming dynasty. Lan Mao notes external use to treat skin and head sores as well as freckles. Internal use of the leaves is first noted in Liu Wen-Tai's Ben Cao Pin Hui Jing Yao , an imperial commissioned work recorded in 1505. Liu Wen Tai notes use of the leaves in the treatment of diarrhea. The leaves of ginkgo are known in Chinese medicine as bai-guo-ye. Recent clinical reports in modern China suggest that the leaves lower serum cholesterol levels and have some clinical value in angina pectoris.
1. Trunk 2. Branches 3. Foliage
In Traditional Chinese pharmacopeia the seeds (with fleshy rind removed) are considered more important than the leaves. The nut, called Pak Ko, is recommended to expel phlegm, stop wheezing and coughing, urinary incontinence and spermatorrhea. The raw seed is said to help bladder ailments, menorrhea, uterine fluxes, and cardiovascular ailments. The powdered leaf is inhaled for ear, nose, and throat disorders like bronchitis and chronic rhinitis. Locally applied boiled leaves are used for chilblains.. The seeds are used as an astringent for the lung, to stop asthma and enuresis.
Ginkgo leaves are a Chinese herb that has been used much more in the West than in its homeland. Over five hundred scientific studies on the chemistry, pharmacology and clinical effects of gingko leaves have been conducted by European researchers over the last 20 to 30 years. The majority of studies on ginkgo leaf extract have involved a product produced by a German/French consortium, referred to in the scientific literature as EGb761.
The extract utilized in medicine is standardized in a multi-step procedure designed to concentrate the desired active principles from the plant. These extracts contain approximately 24% flavone glycosides (primarily composed of quercetin, kaempferol, and isorhamnetin) and 6% terpene lactones (2.8-3.4% ginkgolides A, B, and C, and 2.6-3.2% bilobalide). Other constituents include proanthocyanadins, glucose, rhamnose, organic acids, D-glucaric acid and ginkgolic acid (at most 5 ppm ginkgolic acids). Biochemical studies have concentrated on the flavonoids: much of the curative properties of the ginkgo tree are due to the activities of these flavonoids. The complex extract itself, rather than a single isolated component, is believed to be responsible for Ginkgo's biological activity.
Ginkgo standardized extracts have been widely used in Europe for a wide variety of clinical conditionsassociated with age-related physical and mental deterioration. These include:
1) Alzheimer's Disease / age-related dementia: Ginkgo extracts appear to be capable of stabilizing and, in some cases, improving the cognitive performance of patients with schizophrenia. Based on a quantitative analysis of the literature there is a small but significant effect of 3 to 6 month treatment with 120 to 240 mg of Gbe on objective measures of cognitive function in Alzheimer's Disease ( Oken, Oregon Health Sciences University, 1998 ). The last publication ( Le Bars, Memory Centers of America, New York, Jan 2002 ) indicated that " a treatment effect favorable to EGb could be observed with respect to cognitive performance and social functioning regardless of the stage of dementia, whether mild or moderately severe. However, the relative changes from baseline measured at endpoint depended heavily on the severity at baseline. Improvement was observed in the group of patients with very mild to mild cognitive impairment, while in more severe dementia, the mean EGb effect should be considered more in terms of stabilization or slowing down of worsening, as compared to the greater deterioration observed with placebo". Further research in the area will need to determine if there are functional improvements and to determine the best dosage. Additional research will be needed to define which ingredients in the ginkgo extract are producing its effect in individuals with AD. A recent study makes clear that EGb treatment may enhance the effectiveness of antipsychotic drugs and reduce their extrapyramidal side effects ( Zhang, Yale University School of Medicine, 2001 ).
2) Cardiovascular Disease: Treatment with Ginkgo biloba extract lowers fibrinogen levels and decreases plasma viscosity ( EGb can limit oxidative stress )
3) Cerebral vascular insufficiency and impaired cerebral performance: Administration of EGb has been shown to improve a variety of conditions associated with cognitive functions, particularly for memory loss, attention, alertness, vigilance, reaction times and depressive mood. A recent australian study indicates significant improvements in speed of information processing working memory and executive processing attributable to the EGb ( Stough C, Swinburne University of Technology, Melbourne, 2001 ).
Other therapeutic applications include:
1) Congestive symptoms of premenstrual syndrome: Ginkgo extract was effective for the treatment of the congestive (particularly breast symptoms) and neuropsychological symptoms of PMS.
2) Intermittent Claudication: A recent meta-analysis ( Pittler, University of Exeter, 2000 ) found a significant difference in the increase in pain-free walking distance in favor of Ginkgo biloba (weighted mean difference: 34 meters ). In studies using similar methodological features (ergometer speed: 3 km/h, inclination: 12%) this difference was 33 meters in favor of Ginkgo biloba.
3) Vertigo / Equilibrium Disorder / Prevention of altitude sickness.
4) Tinnitus (ringing in the ear). An overview ( Holstein, Karlsruhe, 2001 ) of results of 19 clinical trials shows a statistically significant superiority of treatment with the Gbe 761 as compared with placebo or reference drugs applied of periods of 1 to 3 months. " Therapeutic success was not directly correlated with either the genesis or the duration of tinnitus. However, investigations of prognostic factors revealed that short-standing disorders have a better prognosis, so that better results can be expected from early-onset treatment."
5) Liver Fibrosis: Ginkgo biloba was shown to be effective in arresting the development of liver fibrosis associated with chronic hepatitis B.
6) Macular degeneration: In spite of the small population sample, a statistically significant improvement in long distance visual acuity was observed in patients with macular degeneration.
Ginkgo Biloba is one of the oldest living tree species, dating back over 300 million years. Individual trees can live for over 1,000 years. Ginkgo Biliboa is the best selling herbal product in the world. It is an extract from the green leaves of the Ginkgo tree which is native to Asia, however, is grown worldwide. The active ingredients in the extract are the Ginkgoflavoneglycos, Bilobalide, and terpenelactones including ginkgolides A, B and C. In Asia, ginkgo tree extracts have been used for over 5,000 years to treat cardiovascular problems as well as lung disorders. Recently, American medical researchers have begun studying ginkgo. In fact, there currently over 3 dozen studies looking at the effects of ginkgo on the human body.
In the last 30 years, more that 300 studies have given clinical evidence that ginkgo prevents and benefits many problems throughout the entire body. Ginkgo is gaining recognition as a brain tonic that enhances memory because of its positive effects on the vascular system, especially in the cerebellum. It is also used as a treatment for vertigo, tinnitus (ringing in the ears) and a variety of neurological disorders and circulation problems. Ginkgo may help to counteract the effects of aging, including mental fatigue and lack of energy.
Ginkgo works by increasing blood flow to the brain and throughout the body's network of blood vessels that supply blood and oxygen to the organ systems. It increases metabolism efficiency, regulates neurotransmitters, and boosts oxygen levels in the brain which uses 20% of the body's oxygen.
Benefits of enhanced circulation in the brain include improved short and long term memory, increased reaction time and improved mental clarity. Ginkgo is often used to treat elderly persons with Alzheimer's and other symptoms of cerebral insufficiency. Cerebral insufficiency is a general term for a collection of symptoms that include difficulties of concentration and memory, absentmindedness, confusion, lack of energy, depressive mood, anxiety, dizziness, tinnitus, and headache.
Ginkgo constituents are beneficial for a variety of imbalances and deterioration in the brain and body. Standardized ginkgo extract inhibits platelet activity factor (PAF), which is a common allergen in the body. Physical stress, and poor quality food can overstimulate PAF production; in other words, blood clotting. Excessive PAF can help cause cardiovascular disease, brain damage, hearing disorders and other immune and inflammatory diseases.
Ginkgo has been used to relieve tension and anxiety and improve mental alertness, elevate mood and restore energy.
Ginkgo has two groups of active substances, flavonoids and terpene lactones, including ginkgolides A, B, and C, bilobalide, quercetin, and kaempferol. The ginkgolides have been shown to control allergic inflammation, anaphylactic shock and asthma.
Ginkgo also acts as a powerful antioxidant and contributes to the oxidation of free radicals which are believed to contribute to premature aging and dementia. Antioxidants also protect the eyes, cardiovascular system and central nervous system.
Ginkgo may also help control the transformation of cholesterol to plaque associated with the hardening of arteries, and can relax constricted blood vessels.
The herb has been used in treatment of other circulation-related disorders such as diabetic peripheral vascular disease, Raynaud's syndrome, hemorrhoids and varicose veins. It can also aid in the treatment of insufficient circulation and complications from stroke and skull injuries. Ginkgo's beneficial effects on the circulatory system also can be of benefit in the treatment of eye and ear disorders.
Studies have confirmed that ginkgo increases blood flow to the retina, and can slow retinal deterioration resulting in an increase of visual acuity. In clinical tests ginkgo has improved hearing loss in the elderly. It also improves circulation in the extremities relieving cold hands and feet, swelling in the limbs and chronic arterial blockage. Among other things, ginkgo is being investigated as a potential treatment to prevent the rejection of transplanted organs, as a treatment for asthma and for toxic shock syndrome.
DISCLAIMER: The information in this column, is NOT intended to diagnose and/or treat any health related issues and is provided solely for informational purposes only. Consult the appropriate healthcare professional before making any changes to your healthcare regime. Even what may seem like simple changes in the diet for example, can interact with, and alter, the efficiency of medications and/or the body's response to the medications. Many herbs and supplements exert powerful medicinal effects. Neither the author, nor the website designers, assume any responsibility for the reader's use or misuse of this information.