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.

 

David