Ginkgo biloba: Improving Your Memory
Dateline: 07/11/98
You've seen the commercials. Commercials that The Natural Apothecary says have resulted in annual sales of more than $2 billion worth of ginkgo. Now I remember where my keys are, what time my doctor's appointment is, and when the grandkids's soccer matches are. All thanks to Ginkgo biloba. And you've wondered, "Is there really anything to this stuff?" When you finish this article, you'll be ready to decide for yourself.
Gingko biloba is the gingko or maidenhair tree, a prehistoric plant that has not changed much in its 150 million years or so of existence. These deciduous trees make wonderful shade trees, with their small, green, fan-shaped leaves that turn the color of butter each fall. If, after reading this, you decide you need one for your yard, make sure you buy the male plant -- the female tree produces messy, nasty smelling seeds that litter your yard.
The Chinese have been, well, nuts about ginkgo seeds for centuries, using them for asthma and bronchitis and other lung conditions. The nuts have powerful expectorant properties (they help you cough up stuff that irritates your airways). According to The Herbalist, the nuts were also used to promote longevity and to increase sexual endurance.
But what we are interested in are the leaves. Ginkgo leaves contain a variety of compounds that have many favorable effects. The Natural Apothecary describes ginkgo's antiinflammatory and antioxidant effects and attributes at least some of those benefits to unique components called ginkgolides. These ginkgolides seem to work by preventing constriction of blood vessels, reducing the stickiness and clotting ability of platelets in the circulation, and blocking the damage and aging effects of oxidation, a normal body process. The Herbalist says these active ingredients reach their highest levels in August and September, so that seems like the perfect time for pruning and harvesting that tree you just planted in the front yard.
One of these ginkgolides, ginkgolide B, has been synthesized by Dr. Elias Corey of Harvard University. This pure compound is being investigated as a potential treatment for transplant rejection and other uses.
How do we get from ginkgolides to memory improvement? Mainly through their effects on circulation. Here's how the theory goes: cerebral insufficiency (a constellation of symptoms including poor concentration and memory, confusion, absentmindedness, and maybe even depression and anxiety) is caused by impaired circulation of blood through the brain. Improve that circulation, and cerebral insufficiency and its attendant symptoms will improve or resolve. Ginkgo improves cerebral circulation by opening up some of the small blood vessels and by keeping platelets from clogging them.
Is there any clinical evidence for this theory? Yes. At least forty clinical trials have investigated the use of ginkgo in the treatment of cerebral insufficiency, and at least eight of those trials were high quality trials (double-blind studies, with patients randomized either to ginkgo or placebo treatment). The results: after taking 120 mg of ginkgo daily for 4 to 6 weeks, patients experienced significant improvement in their symptoms. And side effects were minimal: headaches, dizziness, upset stomach, and the like.
Dramatic claims are also being made for the use of ginkgo in treating dementia and Alzheimer's disease. A review of Ginkgo and Alzheimer's Disease explores the possible mechanisms of ginkgo's effects in these conditions and concludes that there is good rationale for its use in all types of dementia. The author of that article strongly supports its use and backs up his belief with solid evidence. At least one double-blind study, in which 40 patients were randomly assigned to ginkgo or placebo treatment, showed effectiveness in early stage Alzheimer's disease. More clinical trials are underway, particularly in France and Germany, where ginkgo is approved as an over-the-counter drug. Ginkgo is also approved in Canada and the United States as a food or food supplement.
The best place to learn more about Ginkgo biloba is right here at The Mining Co. Check out Herbs for Health to get the latest information on ginkgo.
And for those of you looking for information in other languages, you can also read about ginkgo in German
And, as always, remember to check out available books at Amazon books.
Based on the information available, it looks like the commercials are not just all hype. Regular use of ginkgo leaf extract seems to improve your memory. I don't know about you, but I think I'll rush right out and get my own Ginkgo biloba tree. Now, if I could only find my keys.
Last Updated: 8/10/98