Ginkgo biloba is the oldest living tree species. The Chinese have been using it medicinally for millennia. In recent years, the use of ginkgo biloba has experienced growing popularity.
Ginkgo products should be standardized to provide at least 24% flavone glycosides and contain at least 6% terpene lactones. A 2002 examination of US marketed gingko products found that some products failed to meet the standards that were claimed on the bottle. Therefore caution is advised in product selection.
The ginkgolide class of chemicals has not been found in any other living species to date. The overall physiologic results of ginkgo use are increased perfusion to the brain and peripheral circulation, enhanced free radical scavenging, improved cerebral tolerance to hypoxia, and strengthened microvasculature.
Ginkgo products are sold over-the-counter throughout the world and by prescription in Germany and France. Ginkgo extracts are used for almost any type of vascular disorder associated with spasms, hypoxia, and free radical damage.
Ginkgo has been used successfully in Raynaud’s disease, varicose conditions, dementia syndromes, vertigo and tinnitus of vascular origin, peripheral arterial occlusion, platelet aggregation, and intermittent claudication. Ginkgo is also being investigated for its use immediately after stroke, in asthma, in sexual dysfunction, and in depressive disorders.
Dosage
The typical daily dose of ginkgo biloba for dementia syndromes is 120 to 240mg of a standardized extract. The higher doses are generally required for cerebral disorders. A suggested titration for Alzheimer’s dementia would be 60mg bid for 6 weeks, then increasing the total daily dose by 40 to 60mg every 8 weeks if improvements are not visible.
The daily dose for intermittent claudication, Raynaud’s disease, varicose conditions, and all other previously mentioned disorders is 120 to 180mg. The daily dose should be 60mg bid or tid, because flavones and terpenes have a short half-life. Patients should allow at least 6 to 8 weeks of therapy before maximal benefits are observed.
Adverse Effects
Adverse effects related to ginkgo are relatively mild and infrequent and include headache, diarrhea, dizziness, and occasional allergic dermatologic reactions. However, rare cases of hematomas and bleeding have been reported. Ginkgo’s antiplatelet effect should be considered if the patient is taking other agents with similar blood-thinning actions.
A ginkgo biloba extract (80mg of extract EGb 761 BID) strongly prevented altitude sickness in a trial of 44 people climbing to 17,550 feet. No one in the ginkgo group developed acute altitude sickness, while 40% of those in the placebo group did.
Ginkgo Biloba can help with the following
Alzheimer's Disease
A Ginkgo biloba extract (EGb 761) was tested in Alzheimer’s patients for one year at a daily dose of 120mg. Improvement was experienced in patients with primarily visual impairment, delayed worsening occurred in patients with predominant verbal deficits, and there was a stabilization of symptoms in patients with both types of impairment. [Pharmacopsychiatry 2003;36(Suppl 1): pp.S50-5]
Senile Dementia
A major review of clinical trials provided “promising evidence” that dietary supplements containing the herbal medicine Ginkgo biloba can improve memory and function in people with dementia. Researchers at the Cochrane Collaboration in Oxford reviewed 33 clinical trials and concluded that the remedy appeared to be safe with no excessive side effects.
The medicinal effects of Ginkgo are believed to be gained by causing blood vessels to dilate, thereby improving blood flow to the brain, and through thinning the blood, making it less likely to clot. In addition, Ginkgo probably has some antioxidant effects. [The Guardian October 15, 2002]
Multiple Sclerosis / Risk
Three months of treatment with a Ginkgo biloba product (240 mg/d) maintained attention, memory and functioning, without adverse effects, in double-blind, placebo-controlled study of 23 patients with mild multiple sclerosis. Deterioration of function was observed in patients who had received a placebo. [American Academy of Neurology 54th Annual Meeting, April 13-20, 2002, Denver, Colorado, USA; P06.081]
Intermittent Claudication
In a double-blind German study, ginkgo biloba was significantly superior to a placebo in improving symptoms of intermittent claudication [Peters, 1998]. After six months of treatment, pain-free walking distance in the ginkgo group improved by almost 50% compared to baseline measurements.
Hypertension
One effect of Ginkgo extract is that of promoting vasodilation and blood flow.
Upcoming Surgical Procedure
Ginkgo biloba may increase the risk of bleeding and should be stopped at least 2 days prior to surgery.
Immune System Imbalance (TH2 Dominance)
Gingko Biloba may reduce excess cortisol production. Elevated cortisol levels have a suppressing effect on TH1 cytokines.
Anticoagulant Use
Ginkgo extracts may reduce the ability of platelets to stick together, possibly increasing the tendency toward bleeding. Standardized extracts of ginkgo have been associated with two cases of spontaneous bleeding, although the ginkgo extracts were not definitively shown to be the cause of the problem. There is one case report of a patient taking warfarin in whom bleeding occurred after the addition of ginkgo. People taking heparin should consult with a physician knowledgeable about botanical medicines if they are considering taking ginkgo.
Poor Memory
It turns out that Gingko biloba has no beneficial effect on memory in healthy older people, according to a US study. “Many of our older patients were taking gingko and wanted to know if it was of any benefit. But although there had been dozens of trials showing beneficial effects, they all had serious shortcomings. We decided to carry out the first scientifically rigorous study,” said Paul Solomon who led the study at Williams College in Williamstown, Massachusetts.
Solomon’s team studied 230 adults over the age of 60 who were physically and mentally healthy. They found no memory improvements after six weeks of daily gingko supplementation.
The participants were given 14 standardized tests of learning, memory, attention and concentration. Half of the group were then given daily gingko biloba tablets for six weeks while the rest received a placebo. [NewScientist.com news service, August 2002]
Edema (Water Retention)
Idiopathic cyclic edema is characterized by water and sodium retention with secondary hyperaldosteronism (over-production of aldosterone) due to capillary hyperpermeability. This defect is detected and measured by the Landis’ labeled albumin test; correcting it is important. Ginkgo biloba extract administered either orally or by intravenous infusion provided full correction of this biological anomaly in 10 cases in which the Landis’ test was performed before and after oral treatment, and in 5 cases treated by intravenous infusion. [Presse Med 1986 Sep 25;15(31): pp.1550-3 (translated)]
Tinnitus
Studies have shown a range of responses from nothing more than a placebo to an effectiveness rate of 50%. Gingko must be administered long term (many months) to achieve benefit. Amongst patients suffering from cerebrovascular insufficiency, a common problem associated with normal aging, a gingko extract produced a significant improvement in the symptoms of vertigo, tinnitus, headache and forgetfulness.
Macular Degeneration
Ginkgo Biloba appears to reduce the risk of macular degeneration. [Recent Results in Pharmacology and Clinic, Fuenfgeld FW, ed. Berlin: Springer-Verlag, 1988; pp.231-6]
Vertigo
A double-blind placebo-controlled study of 67 people with vertigo found that 160mg of Ginkgo biloba extract per day significantly reduced symptoms compared to placebo. At the end of the 3-month study, 47% of the ginkgo group had completely recovered, as compared to only 18% of the placebo group.[ Presse Med. 1986;15: pp.1569-1572]
Increased Risk of Alzheimer's / Dementia
“We found that giving a standardized dose of ginkgo biloba over a period of time does not slow down the incidence rate of dementia or Alzheimer’s disease,” said the study’s lead author, Dr. Steven DeKosky, who was chair of the department of neurology at the University of Pittsburgh School of Medicine and Medical Center at the time of the study.
[Journal of the American Medical Association, November 19, 2009]
Cold Hands and Feet
Gingko has an documented reputation for improving circulation, and is sometimes of help for cold hands and feet.
Erectile Dysfunction (ED, Impotence)
Studies show that taking Gingko biloba herbal extract at 240mg daily (usually a 24% extract) can produce improvement in 6 months or fewer, even if previous medications have failed. In a study of 20 patients who had received this conventional therapy, 100% regained the ability to have a spontaneous and sustained erection within 6 months of supplementation. Blood flow into the penis improved within 3 months. [Journal of Sex Education Therapy, Vol. 17, 1991, pp.53-61]
Key
| May do some good |
| Likely to help |
| Highly recommended |
| May have adverse consequences |
Glossary
Perfusion
Usually Coronary/Myocardial perfusion: Flow of blood to the heart and/or blood vessels surrounding the heart.
Free Radical
A free radical is an atom or group of atoms that has at least one unpaired electron. Because another element can easily pick up this free electron and cause a chemical reaction, these free radicals can effect dramatic and destructive changes in the body. Free radicals are activated in heated and rancid oils and by radiation in the atmosphere, among other things.
Over-The-Counter
A drug or medication that can legally be bought without a doctor's prescription being required.
Raynaud's Phenomenon
Raynaud's disease or syndrome is a disorder of blood circulation, mainly in the fingers and toes. It is of unknown cause and characterized by changes of the skin that are aggravated by exposure to cold: first, becoming white with numbness and pain as a result of inadequate oxygenation of the blood, then red/purple with a burning sensation. The sudden constriction of blood vessels causes decreased blood flow to the extremities and can, in extreme cases, lead to gangrene. Also called "white finger", "wax finger" or "dead finger".
Dementia
An acquired progressive impairment of intellectual function. Marked compromise exists in at least three of the following mental activity spheres: memory, language, personality, visuospatial skills, and cognition (i.e., abstraction and calculation).
Vertigo
The sensation of spinning or whirling; a state in which you or your surroundings seem to whirl dizzily.
Tinnitus
A sensation of noise (ringing or roaring) that is caused by a bodily condition and can usually only be heard by the person affected.
Claudication
Often Intermittent claudication: Condition caused by interruptions of blood supply to the muscles, characterized by limping and pain chiefly in the calf muscles: symptom characterized by pain during walking.
Stroke
A sudden loss of brain function caused by a blockage or rupture of a blood vessel that supplies the brain, characterized by loss of muscular control, complete or partial loss of sensation or consciousness, dizziness, slurred speech, or other symptoms that vary with the extent and severity of the damage to the brain. The most common manifestation is some degree of paralysis, but small strokes may occur without symptoms. Usually caused by arteriosclerosis, it often results in brain damage.
Asthma
A lung disorder marked by attacks of breathing difficulty, wheezing, coughing, and thick mucus coming from the lungs. The episodes may be triggered by breathing foreign substances (allergens) or pollutants, infection, vigorous exercise, or emotional stress.
Milligram
(mg): 1/1,000 of a gram by weight.
Alzheimer's Disease
A progressive disease of the middle-aged and elderly, characterized by loss of function and death of nerve cells in several areas of the brain, leading to loss of mental functions such as memory and learning. Alzheimer's disease is the most common cause of dementia.
BID
Twice per day.
TID
Three times a day.
Diarrhea
Excessive discharge of contents of bowel.
Acute
An illness or symptom of sudden onset, which generally has a short duration.
Placebo
A pharmacologically inactive substance. Often used to compare clinical responses against the effects of pharmacologically active substances in experiments.