What Is It?
This popular herbal medicine is extracted from the fan-shaped leaves of the ancient ginkgo biloba tree, a species that has survived in China for more than 200 million years and now grows throughout the world. (The leaves are double, or bi-lobed; hence the name biloba.) Long used in traditional Chinese medicine, it is only in the last few decades that the medicinal uses for the herb have been studied in the West.
Recently ginkgo has received a great deal of attention for its potential as a memory booster. But while the herb has been found to help with age-related memory loss, claims that it’s a “smart pill” and universally useful are dubious. Studies do indicate that the herb can have beneficial effects on the circulatory and central nerve systems, however, and it has been shown to act as an antioxidant as well.
An extract of ginkgo biloba extract (GBE) is used to make the supplement. It is obtained by drying and milling the leaves and then extracting their active ingredients. When buying supplements, look for preparations containing GBE to be sure you get the greatest benefit.
By regulating the tone and elasticity of blood vessels, ginkgo increases blood flow to the brain and extremities, making it particularly useful for circulatory ailments. Research has also shown that ginkgo can enhance the nervous system by promoting the delivery of additional oxygen and blood sugar (glucose) to nerve cells. As an antioxidant, ginkgo mops up the damaging compounds known as free radicals and aids in cell maintenance.
Specifically, ginkgo may help to:
Slow the progression of Alzheimer’s symptoms. Controlled studies have shown that because ginkgo aids blood flow to the brain, it can improve memory in some people with this memory-robbing condition. Findings indicate that it is people already suffering from Alzheimer’s (and other age-related memory problems) who benefit most, not those who are healthy. In a 12-month study of 202 patients with dementia, many of whom also had Alzheimer’s, those given 120 mg of ginkgo biloba extract a day experienced a greater improvement (or stabilization in their mental and social functions) than those given a placebo. The effects were modest and of limited duration, however.
Relieve depression, anxiety, headaches, ringing in the ears (tinnitus), and dizziness. Each of these ailments–like Alzheimer’s–has been linked to reduced blood flow to the brain. In older adults in particular, this problem is often caused by cholesterol buildup in the arteries. By improving blood circulation (including that to the brain), ginkgo may be useful for treating these disorders in older people especially.
Alleviate the symptoms of Raynaud’s disease and intermittent claudication. By improving blood circulation to the extremities, ginkgo helps ease the painful coldness in the hands and feet that is associated with this ailment. It can also reduce the calf cramping and leg weakness of intermittent claudication, a circulatory problem caused by hardening of the leg arteries.
Reduce macular degeneration and control cataracts. Some studies suggest that ginkgo may be of value in treating macular degeneration because it increases blood flow to the nerve-rich fibers of the eyes. The herb’s antioxidant capabilities may also help to neutralize the cell-damaging free radicals that are considered a leading cause of this disorder. Ginkgo biloba’s powerful antioxidant and circulation-promoting properties may also be of help in treating the blurring and dimming of vision caused by cataracts.
Treat complications due to diabetes. Ginkgo has been shown to be useful in treating diabetic neuropathy, the nerve damage resulting from poor circulation to the extremities that is common in diabetes sufferers. Animal studies have shown that ginkgo may also help prevent diabetic retinopathy, an eye disease that can cause blindness.
Counter impotence. Ginkgo biloba extract may enhance the treatment of erectile dysfunction due to poor blood flow resulting from atherosclerosis of the penis. Ultrasound examinations of 60 impotent men who took ginkgo biloba showed improved penile blood circulation after six weeks. After six months, 50% of the patients had regained potency. Continuing studies are investigating ginkgo’s potential in treating this problem.
Reduce the risk of heart attack or stroke. By reducing the “stickiness” of the blood, as aspirin does, ginkgo may lower the risk of blood clots and possibly reduce the risk of heart attacks or stroke. Studies are also evaluating the herb’s effectiveness in speeding recovery from stroke.
Ease asthmatic attacks. Long used in China for this ailment, ginkgo seems to help relieve the airway spasms and wheezing associated with this lung disease.
Optimize brain power. While there are no studies showing that ginkgo can prevent memory loss in healthy people, proponents suggest it can help mental decline and optimize brain function. These effects may be due to ginkgo’s ability to increase blood flow to the brain.
Note: Ginkgo biloba has also been found to be useful for a number of other disorders. For information on these additional ailments, see our Dosage Recommendations Chart for Ginkgo Biloba.
To be sure you’re getting a standardized amount of the herb’s active ingredients, purchase supplements that contain ginkgo biloba extract, or GBE, the concentrated form of the herb. GBE supplements should contain at least 24% flavone glycosides (to maximize the herb’s antioxidant and anticlotting potential) and 6% terpene lactones (for improved blood flow and nerve protection).
As a brain booster and for Raynaud’s disease, intermittent claudication, cataracts, and macular degeneration: Take 40 mg of GBE three times a day, or 60 mg twice a day.
For Alzheimer’s disease, depression, tinnitus, dizziness, impotence, or conditions caused by insufficient blood flow to the brain: Take up to 240 mg of GBE a day.
For diabetes and heart disease prevention: Take 40 mg of GBE three times a day.
For asthma: Take 40 mg of GBE three times a day, increasing the dose up to 240 mg a day when asthma is acute.
Be sure to check out our Dosage Recommendations Chart for Ginkgo Biloba, which lists therapeutic dosages for specific ailments at a glance.
Guidelines for Use
It commonly takes four to six weeks, and in some cases up to 12 weeks, to notice the herb’s effects.
You can take ginkgo with or without food.
Costs vary considerably so shop carefully for the lowest price on a quality product.
Because ginkgo reduces the rate at which blood clots, people who are on anticoagulants or who suffer from clotting disorders should consult a doctor before taking this herb.
Ginkgo intensifies the blood-thinning effect of long-term aspirin use and may lead to excessive bleeding.
Note: For information on interactions with specific generic drugs, see our WholeHealth Chicago Drug/Nutrient Interactions Chart.
Possible Side Effects
Generally, ginkgo is considered safe for long-term use in recommended dosages, but higher doses (above 240 mg a day) can lead to intoxication or disorientation.
In rare cases, ginkgo may cause headache, irritability, restlessness, diarrhea, headache, nausea, vomiting, dizziness, or vertigo. These effects are usually mild and transient.
If side effects are bothersome, discontinue taking the herb or reduce your dosage.
Don’t use unprocessed ginkgo leaves in any form, including teas; they contain potent chemicals (allergens) that can trigger allergic reactions. Stick with standardized extracts (GBE); the allergens are removed during processing.
Aging 40 mg GBE 3 times a day or 60 mg GBE twice a day or 350 mg freeze-dried ginkgo biloba leaf 3 times a day
Allergies 40 mg ginkgo biloba extract (GBE) 3 times a day or 60 mg GBE twice a day or 350 mg freeze-dried ginkgo biloba leaf 3 times a day
Alzheimer’s Disease 80-120 mg GBE 3 times a day
Asthma 40 mg GBE 3 times a day. Dose may be increased to 240 mg GBE a day when asthma is acute.
Cataracts 60 mg GBE twice a day
Depression 60 mg GBE 3 times a day
Diabetes 40 mg ginkgo biloba extract (GBE) 3 times a day, or 60 mg GBE twice a day, or 350 mg freeze-dried ginkgo biloba leaf 3 times a day
Fibromyalgia 80 mg GBE 3 times a day
Impotence 60 mg GBE 3 times a day
Macular Degeneration 40-60 mg GBE twice a day or 350 mg freeze-dried herb twice a day
Memory Loss/Impairment 40-60 mg GBE 3 times a day or 350 mg freeze-dried whole herb 3 times a day
Menopause 40 mg ginkgo biloba extract (GBE) 3 times a day, or 60 mg GBE twice a day, or 350 mg freeze-dried ginkgo biloba leaf 3 times a day
Multiple Sclerosis 60 mg GBE 3 times a day
Perimenopause 40 mg ginkgo biloba extract (GBE) 3 times a day, or 60 mg GBE twice a day, or 350 mg freeze-dried ginkgo biloba leaf 3 times a day
Raynaud’s disease 60 mg GBE 3 times a day
Stroke 80 mg GBE 3 times a day
Tinnitus 80 mg GBE 3 times a day
David Edelberg, M.D.
Best known as a popular memory enhancer, the herb ginkgo biloba has been shown in some studies to have significant antidepressant properties as well. Precisely how it does this–or its mechanism of action–is uncertain, but ginkgo probably combines improved circulation to the brain with some effect on neurotransmitters, the chemicals that transmit signals between nerve cells. The herb appears to be extremely safe, even when taken over the long-term, and it can be used in combination with prescription antidepressants. However, if you’re taking an anticoagulant medication such as warfarin, consult your doctor before combining.
WHAT TO LOOK FOR
Scientific studies are generally performed using ginkgo biloba extract, or GBE. And you may prefer to stick with reputable brands that state a guaranteed potency on the label. Look for GBE supplements standardized to contain at least: 24% flavone glycosides (organic substances responsible for the herb’s antioxidant and anticlotting abilities) 6% terpene lactones (primarily compounds called ginkgolides and bilobalides, which appear to improve circulation and protect the nerves). However, this suggestion is certainly not mandatory. Ginkgo has been used to “benefit the brain” in traditional Chinese medicine for more than 3,000 years–certainly long before anyone considered “standardizing” anything. Taking the freeze-dried whole herb is another viable option.
The dose for ginkgo when used for depression is a little higher than that recommended for memory enhancement. You need to take at least 60 mg but even as high as 80 mg three times a day; this is a bit inconvenient but necessary. Ginkgo has a short half-life, which means it disappears quickly from the blood stream, and more frequent dosing is needed. It also takes a while to become effective, commonly six to eight weeks, but sometimes as long as 12. The liquid extract is concentrated, so it’s usually 1 to 1 1/2 ml three times a day. But carrying around a bottle can be a mite inconvenient, especially if it accidentally opens and leaks onto that valuable piece of electronic ginkgo, otherwise known as your Palm Pilot. In that case, look for capsules from a reputable manufacturer (they generally come in 40 mg, 60 mg, and 80 mg strengths).
David Edelberg, MD