Ginkgo biloba for Prevention of Dementia — Forget About It

Several preclinical studies have suggested that Ginkgo biloba extract is neuroprotective, although some treatment studies (including meta-analyses) have shown little cognitive benefit. Americans are estimated to spend $100 million yearly on gingko in the hope that it enhances memory or prevents memory loss. To ascertain whether G. biloba prevents all-cause dementia and Alzheimer disease, researchers conducted the Ginkgo Enhancement of Memory (GEM) study, a multisite, randomized, controlled 6-year trial.

Steven T. DeKosky, MD; Jeff D. Williamson, MD, MHS; Annette L. Fitzpatrick, PhD; Richard A. Kronmal, PhD; Diane G. Ives, MPH; Judith A. Saxton, MD; Oscar L. Lopez, MD; Gregory Burke, MD; Michelle C. Carlson, PhD; Linda P. Fried, MD, MPH; Lewis H. Kuller, MD, DrPH; John A. Robbins, MD, MHS; Russell P. Tracy, PhD; Nancy F. Woolard; Leslie Dunn, MPH; Beth E. Snitz, PhD; Richard L. Nahin, PhD, MPH; Curt D. Furberg, MD, PhD; for the Ginkgo Evaluation of Memory (GEM) Study Investigators 

Published in JAMA The Journal of the American Medical Association 2008;300(19):2253-2262.

In summary, in this randomized clinical trial in 3069 older adults with normal cognitive function or mild deficits, G biloba showed no benefit for reducing all-cause dementia or dementia of the Alzheimer type. A central issue in testing of complementary and alternative medications is the formulation of the compounds. This study used a requisite standardized formulation of G biloba extract with specified amounts of the active ingredients in a dosage based on the highest doses used and reported in the literature. The extract we tested is among the best characterized and is the one for which the most efficacy data are available. Thus, we believe that the results are applicable to other G biloba extracts. Based on the results of this trial, G biloba cannot be recommended for the purpose of preventing dementia.

I’ve personally had the pleasure of meeting Dr. Steven T. DeKosky, MD. Dr. DeKosky had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.  I am quite pleased and fortunate to have Dr. Oscar L. Lopez , MD as my personal neurologist at the University of Pittsburgh Medical Center (UPMC).

This well-planned and well-executed study definitively answers the question of whether G. biloba prevents dementia. Considering the lack of efficacy reported here, these measures are unlikely to yield positive findings.

In the present economy, can people put the $100 million to better use? I don’t know the answer to this. However, I would not criticise anyone for taking and/or considering taking Gingko biloba.

Ckick here for the Gingko Fact Sheet.





10 Responses

  1. Hello David…thanks for the info on Ginko Biloba. I also wanted to put in my 2 cents on the caution of using some of the herbal remedies if you have high blood pressure. I know Ginko is one you should avoid if you do have high blood pressure. Keep up your writing. It is inspiring.


  2. Hi David, I’ve never been a believer in all the herbs and extracts, etc.
    from health food stores or sold by individuals. Yes, a few vitamins in their
    place are good, but some of this has gone over board. My ex husbands wife wanted
    me to take a natural herb—It’s all natural—- she relayed to my son who
    in turn was trying to get me to take it. I said Son, I am allergic to so many
    things that are all natural that I won’t take it. It may send me to the
    hospital. What we don’t understand can kill us.

  3. Actually, I’ve been taking gingko on and off for many years. I started taking it for my memory which has never been good. When it didn’t help, I stopped and I noticed that I started having slight vertigo episodes. I have them occationally when I lay down but they stopped. Then I heard on one of those health talk shows on the radio that gingko is good for vertigo. Bingo! It also worked for some people I gave it to.

  4. Be careful with the Ginko, it can thin your blood. We discovered this when my mother had surgery and couldn’t stop bleeding after. In pre-op, someone had missed that she was taking this supplement.

    Make sure you tell your doc if you are taking Ginko and are having surgery.

  5. Oh wow…thanks for mentioning that…my Mom had been talking about trying to get my Dad to take the Ginko…he’s on coumadin and a VERY low dose of that is keeping his blood thin enough to manage…
    Don’t think he needs to take anything else to thin it down further. We’ve had problems with him taking his meds…had him on Aricept, but when he found out it was for Alzheimer’s, he literally threw it out in the yard…now, we’ve got him on Namenda and are just telling him that it’s for his shoulder pain. Hate to lie to him, but it’s the only way to get him to take it.

  6. People forget that vitamins and other supplements are also drugs. If possible, it’s best to run things past your dr before you start taking natural supplements. It’s true that some dr don’t believe in anything a pharmacy company didn’t make, but some will be open minded and some might know of possible bad interaction with medications that you are taking.

  7. You can also use any of the sites that give info about drug interactions – they will usually alert you to possible overlaps. And they do typically include supplements. I just tried – the top line offers a menu choice for Check Interactions. I put in Coumadin and Ginko, and it said this:

    GINKGO BILOBA may interact with WARFARIN SODIUM (in Coumadin Tablets)

    Ginkgo contains chemicals that can reduce the stickiness of blood components called platelets. Platelets are partly responsible for forming blood clots that stop bleeding from injuries or other types of damage to the blood vessels. When taken together with drugs like warfarin that also decrease the blood’s ability to clot, ginkgo may increase the risk of dangerous bleeding. In general, ginkgo should not be taken while warfarin is being used.

  8. Guess I better stop drinking tea with Ginkgo in it. I remember studying about plants in school I wonder if this Ginkgo is from the Ginkgo tree which is said to be to be slightly poison? Least ways that is the way I remember it.

  9. I remember learning something about Ginkgo being a poison years ago. It is a tree or a large bush I believe and our high school class studied trees for class.

  10. Contrary to you I do believe Ginko improves cognitive functions because it has improved my mothers faculties.
    I can however not get over the conflict of interest between the pharmaceutical industry and the scientific reserach.
    Of course you are a physician and believing there is something worng with all that will put your entire life under a difficult light.
    If alternative medicine does not work why would we spend so much money on it?
    I am not an MD but I am a Master of Sciences and I do not need a doctor to see what works. For me many herbal remedies do work.
    I cured myself of endometriosis when doctors believe it is incurable.
    Because people can think for themselvesand canexperiment with their life they go for herbal treatements which do not give side effects and help improve our quality of life.
    These are the reasons why we spend money on herbals.
    By the way I am not an american. English is not my moother language.

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