Vol. 2, #18
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


1. Trunk

   A Ginkgo biloba tree can reach 30 or 40 meters  height and a spread of 8 meters. The trunk can become about 3 or 4 meters wide in diameter. It is straight columnar and sparingly branched. Young trees have usually a central trunk, pyramidal in shape, with regular, lateral, ascending, asymmetrical branching . The bark is brown and rough. It fissures rough furrows with the age.

The male tree usually has a slim column form and is slightly longer, the female tree has a wider crown and a more spread out form.

 

Male tree Female tree
round and squat tree fastigiate tree
small and pointed burgeon big and rounded burgeon
budding more early (15 days to 3 weeks)

.

leaves fall more early ( 2 to 3 weeks)

 

2. Branches

   The Ginkgo biloba tree has long and short branches growing at right angles. A short branch may become a long branch and the tip of a long branch may change into a short branch. That's why older trees may have a more irregular form. The leaves grow alternate on the long branches during spring. On the ends of short, lateral shoots they grow very slowly in clusters and produce a long shoot with scattered leaves after a number of years. 

3. Foliage

   The leaves of this tree are interesting and unique from any other tree. They are fan-shaped, leathery and smooth. They are often deeply grooved in the middle of the leaf, producing two distinct lobes, hence the name Ginkgo biloba (two lobes).  The leaves have a venation pattern that is open dichotomous; the veins fork in pairs from the base of the leaf, and are not cross-connected. They are bright green during the summer, turning gold before dropping in the fall. However, leaves fall quickly and the fall color show is short!

 

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 leaf extracts have been shown to have a wide range of biological activities. The most well-known use is the ability to improve short term memory. Other important effects include a protective effect on the blood-brain barrier and an anti-radical (antioxidant) effect. The leaf extracts has also been shown to increase vasodilation and peripheral blood flow rate in capillary vessels and end-arteries in various circulatory disorders. Ginkgo leaf helps to maintain integrity and permeability of cell walls by inhibiting lipid peroxidation of membranes. Other studies have shown vascular-tone regulating effects, and help in modulating cerebral energy metabolism.

 

 

  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 tree was discovered in China in 1690 by Kaempfer who wrote the first scientific description of this tree. He suggested the Ginkgo name. This name is derived from the Chinese YIN , silver, and HING , apricot, in reference to appearance of the fruit. Ginkgo trees grow well in the city, being able to tolerate city dust and pollution. It isn't usually vulnerable to fungi, insects or damaged by storms

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.

Ginkgo's most powerful effect is on the circulating system. Ginkgo flavenoids directly dilate the smallest segment of the circulating system, the micro-capillaries, which increase both blood circulation and oxygen levels in the brain as well as in other critical organ tissues. Ginkgo also prevents platelet aggregation or clumping inside the arterial walls. This increases arterial wall strength and flexibility and decreases the opportunity for the formation of arteriosclerostic plague. Since ginkgo increases oxygen flow to the brain and enhances the brains uptake and utilization of glucose it also is being researched for its role in the senility, forgetfulness, headaches and Alzheimer's disease and its role in improving alertness, memory and mental performance.

Related to circulatory improvement, German researchers have also been studying ginkgo as a treatment for atheroclerotic peripheral vascular disease. This disease impairs walking and ginkgo has been shown to help blood flow to the legs allowing people to walk further with far less pain.

Aside from these critical, high profile circulatory effects, ginkgo also increase the body's ability to produce the universal energy molecule adenosine triphosphate (ATP). This can in turn, decrease fatigue and listlessness.

Ginkgo is a highly important antioxidant shown to have a special affinity for scavenging the superoxide radicals. Due to its antioxidant role, ginkgo can increase cellular longevity, protect against pulmonary disease, provide membrane stability, and support ocular strucular integrity (i.e.. prevent maculos degeneration).

There are a variety of different Ginkgo Biloba raw materials available to manufacturers for use in brand name products. The raw materials chosen is a key in the effectiveness of the final product.

Ginkgo leaves should be hand picked to insure that the plant's terpene rich veins are not distroyed. Once harvested, the leaves need to be dried to an extract moisture level to maintain active constituent potencies. After drying the leaves must be stored in temperature and humidity controlled warehouses until the extraction process occurs. Following extraction, there should be a guaranteed potency of a minimum of 24% ginkgoflavonglycosides and 6% total terpenelactones.

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.

Side effects: No major adverse effects seen in any clinical trials of Ginko Biloba. Rare minor side effects reported are mild gastrointestinal discomfort & headache. Very large doses may cause diarrhea, nausea, vomiting & restlessness.
Herb/drug interactions: May have anticoagulant effect when taken with aspirin, coumadin or other blood-thinning drugs or supplements.

Ginkgo trees, like some conifers and cycads, are dioecious, producing pollen and seeds on separate trees.  It is difficult to differentiate the sexes of the young individuals, it is necessary to wait the first flowering (not before 40 years!). Both pollen cones and seed structures grow from the spur shoots, among the leaves. Each pollen cone bears several pollen sacs. The pollen is transported by wind and produces motile sperm, not seen in the later-evolving conifers and angiosperms. The japan botanist Hirase 1856-1925) observed motile spermatozoids for the first time in the Botanical Garden of Tokyo University on September 9, 1896.

 The pollen cones appear in the early spring, while ovules appear in the fall and are shed with the leaves. The pseudo- fruits resemble small plums when ripe. They are about ½ inch in diameter. They contain a large, smooth, silvery-white seed in the center. When the fruits begin to decay after they've fallen, they emit an unpleasant odor. The Ginkgo nuts can be roasted; they are valued by the Oriental people. 

 Ginkgo disseminates neither spores (like the ferns), nor seeds (like the graminaceous ones) but something intermediary: the ovule. The ovule is the whole of the female reproductive cells i.e. the oosphere (haploid) and is additional (nucellus) They are large ovules, stuffed substances of reserve, that Ginkgo drops on the ground rather tardily in season. With the higher pole of the ovule is constituted a mini cavity filled with liquid: the pollinic room. This room presents a tiny opening, the micropyle, which produces a viscous droplet  to trap a grain of pollen if it is presented and the micropyle is closed then. Finally pollen germinates then and produces  true spermatozoïdes which swim towards the female cell and penetrate to amalgamate with it.

The fruits are often produced in great abundance and becoming an abscissing mushy mess in October, covering the ground with fleshy, strongly malodorous fruits. They then release a very nauseous odor, of a type of rancid butter, due to the presence of butyric acid. Moreover, as they are viscous, the presence of a great quantity of ovules on the roadway or on a pavement can be at the origin of accidents. Finally this pulp contains irritating and allergic substances for certain people; its handling starts  cutaneous pruriginous injuries. In fact, urban landscapers recommend only the male tree. 

Whether there is fecundation of the spermatozoïde with the oosphere  or not, the ovules enlarge and accumulate their reserves. It is a great wasting of energy for a result which can be very poor if, after a very cold time, this fecundation is not carried out.  The development is continuous and in the event of hostile environment, the seed will not be able to wait until the conditions improve. The transformation in seeds of plants with "ovules" is not effective.


    Food and Cooking 

        Ginkgo nuts have long been regarded as a delicious food by Japanese people, and these have been cooked and served in various ways depending on the time. Ginnan is the Japanese word for those seeds. Ginnan appear as a fruit or as tea cake in a textbook called Matsuya Kaiki (1533-1596), which is a series of records of tea ceremonies.

    In the Edo period, Ginkgo nuts came to be eaten by the common people. They are often regarded as a side dish when drinking sake. The most common ways of preparing Ginkgo nuts today are grilling them or boiling them in chawan-mushi ( recipe on www.kamada.co.jp ), a pot-steamed egg dish. 

Furthermore, grilled nuts are still often eaten by the Japanese today when they drink sake. When seeds have been taken to excess during food shortages, Ginnan food poisoning  has sometimes occured in Japan. Ginnan food poisoning is caused by MPN (4-O-methylpyridoxine) that bas an antivitamin B6 activity. The symptoms of this poisoning are mainly convulsions and loss of consciousness. However, children are most susceptible to this type of food poisoning, and it is recommanded that consumption of Ginkgo seeds be limited to not more than five for children under 6 years.


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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.

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