Vascular & Cognitive Benefits of Ginkgo biloba

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Vascular & Cognitive Benefits of Ginkgo biloba

JoAnn Guest

Nov 04, 2004 21:02 PST

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Vascular & Cognitive Benefits of Ginkgo biloba

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Extracts from the leaves of the ginkgo biloba tree have been used

therapeutically in China for millennia. According to fossil records,

the ginkgo tree has been around for over 200 million years and is

one of the oldest still existing tree species on earth. Individual

trees live up to 1,000 years. Ginkgo, like ginseng, is mentioned in

the traditional Chinese pharmacopoeia.

 

Ginkgo extracts are among the most widely studied and prescribed

drugs in Europe to alleviate symptoms associated with a wide range

of conditions.

 

The main indications for these extracts are peripheral

vascular disease and the therapy of age related cognitive decline.

Ginkgo biloba is a mind booster underutilized by the medical

profession.

 

 

 

What's in Ginkgo biloba?

 

Ginkgo contains many different substances but most of them fall into

two main categories:

 

Terpenoid lactones and Flavonoids. The most unique components of

ginkgo extracts are the terpene trilactones which are

structurally complex molecules. Terpene lactones give ginkgo a

bitter and strong flavor. The most important terpenes are the

ginkgolides and bilobides. Ginkgolides have not yet been found in

any other living plant species.

 

Other compounds in ginkgo biloba include proanthocyanidins,

carboxylic acids and non-flavone glycosides

 

Flavonoids are natural substances that are also found in fruits and

vegetables. Flavonoids act as antioxidants, have an influence on the

immune system,

and interfere with tumor formation.

 

Ginkgo contains many flavonoids but the most concentrated are

kaempferol, quercetin, and isorhamnetin. Most ginkgo products on the

market list a flavonoid concentration of 24%. You will often see 24%

printed on packages or bottles of ginkgo.

 

How Does Ginkgo Work?

 

The active ingredients in gingko are believed to have their

beneficial effects by acting as antioxidants, preventing red blood

cells and platelets from aggregating to form clots,

allowing more oxygen to reach neurons, and improving circulation in

tiny blood vessels by inducing relaxation of the muscles surrounding

blood vessels.

 

Even circulation to the eyes improves when subjects are given

ginkgo.

 

Clinical Uses of ginkgo biloba

 

The primary indications for ginkgo biloba are age related cognitive

decline (ARCD) and Alzheimer's disease. Age related cognitive

decline is a term that describes a collection of symptoms. These

include difficulty in concentration and memory, absent-mindedness,

confusion, lack of mental energy, and sometimes, depressive mood.

 

Some of these symptoms may be associated with not enough blood

reaching the brain, hence a potential justification for the use of

gingko in lessening these symptoms.

 

Ginkgo improves communication between nerve cells and enhances blood

flow to the brain.

 

It is licensed in Germany for the treatment of ARCD. Ginkgo may have

promise in the treatment of Parkinson's disease and Alzheimer's when

used together with other conventional medicines.

 

A well publicized study-

in the Journal of the American Medical Association indicated that

120 mg of ginkgo extract per day for one year was able to slightly

improve cognitive performance in patients with Alzheimer's disease.

 

Ginkgo may show a beneficial effect on attention, memory and

functioning in Multiple Sclerosis patients.

 

Patients with dementia are helped by ginkgo.

 

It is unlikely that those with normal memory function will

notice a significant effect from ginkgo.

 

 

Ginkgo and Liver

 

Ginkgo is able to protect the liver from damage since it has

antioxidant properties,

 

prevents *lipid* peroxidation

 

and replenishes the glutathione level.

 

The effects of ginkgo were comparable to that of silymarin.

 

 

What Dosages of Ginkgo Are Best?

 

The majority of the studies done thus far with ginkgo have used

daily dosages of 120 to 160 mg (50:1 concentration, 24% flavonoids).

Patients generally took 40 milligrams three to four times a day.

Treatment may be needed for a few weeks before positive results can

be fully appreciated.

 

 

Most manufacturers have pills that contain 40 or 60 mg of ginkgo.

You may wish to start with one 40 mg pill a day to see if there

is any improvement in memory or thinking. Ginkgo is best taken early

in the day, and no later than afternoon.

Ginkgo has anti-platelet activity and hence may prolong the time it

takes to form a blood clot (thrombus).

 

However, a study published in April, 2003 indicates that Coenzyme

Q10 and Ginkgo biloba do not influence the clinical effect of

warfarin.

An additional study did not find ginkgo to alter platelet " function "

or coagulation time.

 

Ginkgo Summary

 

Ginkgo biloba appears to be useful in memory loss due to aging or

Alzheimer's disease, but is probably of little benefit in the young

who have normal brain function and memory.

 

Middle aged and older individuals may find ginkgo to be helpful in

sharpening the mind. For more details, see Mind Boosters book.

 

Because of its antioxidant properties, it may be useful in

individuals with cerebrovascular disease.

 

Due to its blood thinning properties, a dose of 60 mg a day should

not be exceeded on a daily,

long-term basis unless a health care provider monitors you. Keep in

mind that other nutrients and drugs have blood-thinning properties

including coumadin, fish oils, and vinpocetine.

 

Ginkgo Research Update

 

Age-related effects of Ginkgo biloba extract on synaptic plasticity

and excitability.

Williams B.The Scripps Research Institute, 10550 North Torrey Pines

Road, La Jolla, CA 92037, USA. Neurobiol Aging. 2004 Aug;25(7):955-

62.

 

EGb 761 is a standardized extract from the Ginkgo biloba leaf and is

purported to improve age-related memory impairment. The acute and

chronic effect of Ginkgo biloba on synaptic transmission and

plasticity

in hippocampal slices from young adult (8-12 weeks) and aged (18-24

months) C57Bl/6 mice was tested because hippocampal plasticity is

believed to be a key component of memory.

 

Acutely applied Ginkgo biloba significantly increased neuronal

excitability in slices from aged mice by reducing the population

spike threshold and increased the early phase

of long-term potentiation, though there was no effect in slices from

young adults.

 

In chronically treated mice fed for 30 days with an Ginkgo

biloba-supplemented diet, Ginkgo biloba significantly increased the

population spike threshold and long-term potentiation in slices from

aged animals, but had no effect on slices from young adults.

 

The rapid effects of Ginkgo biloba on plasticity indicate a direct

interaction with the glutamatergic system and raise interesting

implications with respect to a mechanism explaining its effect on

cognitive enhancement in human subjects experiencing dementia.

 

Ginkgo biloba special extract EGb 761 in the treatment of peripheral

arterial occlusive disease (PAOD)--a review based on randomized,

controlled studies.

 

Surgical Department, Hospital Porz/Rhein, Koln, Germany.

Int J Clin Pharmacol Ther. 2004 Feb;42(2):63-72.

 

OBJECTIVE: The present review gives an overview and evaluation of

clinical studies proving the efficacy of Ginkgo biloba special

extract EGb 761 in patients with PAOD. Relevant original papers and

reports on this topic were identified by means of a literature

search.

 

Only randomized, double-blind, placebo-controlled clinical trials in

patients with the indication peripheral arterial occlusive disease

in stage II were included (only treatment with the oral form of

Ginkgo biloba.

 

For the selected studies the ratio theta of the walking distance

between Ginkgo biloba and placebo was calculated and a test for

relevant superiority of Ginkgo biloba was performed.

 

In the majority of the studies, there was an advantage of Ginkgo

biloba in the increase of pain-free walking distance compared to

placebo.

 

For 7 studies, the advantage was found to be statistically

significant.

Testing the relevant superiority showed a significant result in 6 of

the selected studies. The pooled estimator of the ratio amounts to

theta = 1.23 (95% CI: 1.16, 1.31) and demonstrates the efficacy of

Ginkgo biloba over placebo as well.

 

CONCLUSIONS: This review confirms the efficacy of

Ginkgo biloba special extract EGb 761. It demonstrates not only the

statistical significance of the difference of Ginkgo biloba with

respect to placebo but also the clinical relevance for the treatment

of patients with PAOD.

 

 

The effect of ginkgo biloba on healthy elderly subjects

Cieza A, Maier P, Poppel E.

Fortschr Med Orig. 2003;121:5-10.

 

BACKGROUND AND AIM: Over the past 25 years, numerous studies have

confirmed the positive effect of the special ginkgo biloba extract

EGb 761 on the mental ability and emotional well-being of patients

with cognitive disorders of vascular genesis, and Alzheimer-type

dementia.

 

The following study investigated the short-term effect of the

special ginkgo extract EGb 761 on the subjective emotional well-

being of healthy elderly subjects. The study was designed as a

randomized double-blind, monocenter study with parallel groups. It

included 66 healthy subjects of both sexes aged between 50 and 65

with no age-related cognitive

impairments. For a period of 4 weeks, 34 subjects received a daily

dose of 240 mg ginkgo biloba , and 32 a placebo.

 

RESULTS: The final examination revealed a statistically significant

difference between the two groups for the VAS mental health and

quality of life, as also for SIS Mood at the telephone interview in

week 2. A comparison of baseline with the final examination within

the groups showed a statistically significant improvement in the

ginkgo biloba

group for the variables: depression, fatigue, anger and SDS.

 

 

For none of the variables investigated was a worsening observed in

the ginkgo biloba group.

 

CONCLUSIONS: The results suggest a positive effect of ginkgo

biloba on the subjective emotional well-being of healthy elderly

persons.

 

 

Ginkgo biloba extract EGb 761 in dementia: intent-to-treat analyses

of a 24-week, multi-center, double-blind, placebo-controlled,

randomized trial.

Kanowski S, Hoerr R. Psychiatrische Klinik und Poliklinik der Freien

Universitat Berlin. Pharmacopsychiatry. 2003 Nov;36(6):297-303.

 

In 1996, Kanowski et al. reported about the beneficial effects of

ginkgo biloba special extract EGb 761 (240 mg/day) in outpatients

with

pre-senile and senile primary degenerative dementia of the Alzheimer

type (DAT) and multi-infarct dementia of mild to moderate severity.

 

After 24 weeks of treatment, the ITT analysis of the SKT and

estimated ADAS-cog scores revealed a mean decrease in the total

score by -2.1

points and -2.7 points, respectively, for the ginkgo biloba group,

which indicates an improvement in cognitive function. On the

contrary, the placebo group exhibited only a minimal change of -1.0

and -1.3 points, respectively.

 

The Clinical Global Impression of Change (CGI, Item 2) favored the

ginkgo biloba group with a mean difference of 0.4 points. Changes in

the rating related to activities of daily living showed a favorable

trend for ginkgo biloba.

 

The results of this ITT analysis substantiate the outcomes

previously obtained with a responder analysis of the per-protocol

population and confirm that ginkgo biloba improves

cognitive function in a clinically relevant manner in patients

suffering from dementia. The therapeutic effect is in line with the

outcome of another ginkgo biloba study conducted in the U.S.

 

A placebo-controlled, double-blind trial of Ginkgo biloba for

antidepressant-induced sexual dysfunction.

Kyungpook National University, Taegu, South Korea.

Hum Psychopharmacol. 2002 Aug;17(6):279-84.

 

The aim of this study was to examine the effect of Ginkgo biloba on

antidepressant-induced sexual dysfunction. The Ginkgo biloba (n=19)

and the placebo groups (n=1 were divided; each to be administered

with

Ginkgo biloba and placebo respectively for 2 months by means of a

randomized placebo-controlled, double-blind study. The results of

this 2 month trial were: (1) there was no statistical significant

difference from the placebo at weeks 2, 4 and 8 after medication;

(2) in comparison with baseline, both the Ginkgo biloba group and

the placebo group showed improvement in some part of the sexual

function, which is suggestive of the importance of the placebo

effect in assessing sexual function. This study did not replicate a

prior positive finding supporting the use of Ginkgo biloba for

antidepressant, especially SSRI, induced sexual dysfunction.

 

Emails about Ginkgo

 

I found that flax oil/fish oil along with vinpocentine in a small

dosage and as well ginkgo, again in a small amounts eliminates the

symptoms of Meniere's disease. I had all the symptoms for about a yr

and a half. and finally i decided i would do something myself as i

could not function

and was offered no solution other than a lot of very expensive tests

and procedures. " yep, you got a problem! " or expensive words to that

effect.

 

Q. Just thought I would mention that I have found ginkgo to be a

wonderful supplement for the treatment of tinnitus (ringing in the

ears) that was do to exposure to loud noise as a teenager. I would

notice a significant improvement a day or two after taking the

supplements (100mg 2x daily 24% standardization) and the ringing

would gradually return

after I would stop taking them. After using it on and off for

several

years the problem has faded into the background and they are now

unnecessary. I observed no improvement in memory or concentration,

though I might have been taking too little.

 

A. Thanks for your feedback. Some studies do show ginkgo helpful for

tinnitus, although my clinical experience with this herb for

tinnitus has not shown a consistent beneficial response.

 

http://www.raysahelian.com/ginkgo.html

_________________

 

JoAnn Guest

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