Ginkgo Biloba, Memory & Cognitive Health

Regular readers of this column know that I have astudy, while the "control group" of patients received
strong interest in lifestyle- and diet-based approachesan identical-appearing placebo ("sugar pills) twice daily.
to disease prevention, but that I insist on rigorous,(As this was a double-blind study, neither the patient
high-quality research-based data before I canvolunteers nor the researchers knew which patients
recommend a particular lifestyle or dietarywere receiving Gingko pills and which were receiving
modification to my readers (or to myself). Many pastthe placebo pills until after the research study was
columns have reviewed the findings of researchcompleted.)
studies with favorable results associated with specificMultiple validated cognitive screening exams were
nutritional or other lifestyle approaches to diseasegiven to all of these older patient volunteers during
prevention. However, this week's column will reporteach year of the study, and the rate of annual
on a newly published prospective clinical research trialdecline in cognitive function was then compared
that calls into question the supposed clinical value ofbetween the two groups of patient volunteers.
the traditional Chinese medicine herb Ginkgo biloba inAreas of cognitive function that were specifically
reducing the cognitive decline associated with agingtested for in this high-powered prospective clinical
and Alzheimer's disease.research trial included memory, attention, visual-spatial
Previously published public health research data, basedabilities, language function, and overall executive brain
upon low-powered research methods, havefunction. (Note: these same cognitive function tests
suggested that dietary supplementation with Ginkgoare also routinely utilized to assess cognitive function
biloba might be able to improve memory andin patients with Alzheimer's disease.)
cognition, particularly in older adults. However, moreUnfortunately, there was absolutely no difference
recent data, based upon more robust types of clinicalobserved or measured in the rate of decline in
research, have called this assumption into questioncognitive function between the two groups of older
(as well as previous claims that Gingko biloba canpatient volunteers, indicating the lack of any clinically
delay or reverse the cognitive decline associated withdetectable benefit in age-related cognitive decline
Alzheimer's disease). Now, a newly publishedassociated with high-dose supplementation with
prospective, randomized, double-blind,Ginkgo biloba.
placebo-controlled clinical trial of Gingko biloba(As an editorial aside, the Journal of the American
supplementation in older adults in the United StatesMedical Association (JAMA) is to be commended for
appears to have definitively resolved the controversypublishing this rigorously performed clinical research
about the value of Gingko biloba in maintainingtrial and its Level One research findings, as there is a
memory, and other high level cognitive functions, inwell-known bias against publishing clinical research
older adults.studies with "negative findings," such as this study,
Ginkgo biloba trees are often referred to as livingamong prestigious medical journals.)
fossils, as they are known to survive for 1,500 yearsAlthough this is the second recent high-level
or more, and their presence has been documentedprospective clinical research trial that has found
within fossil-bearing rocks more than 270 million yearsabsolutely no clinical benefit in preserving or improving
old. Although ancient fossils containing the distinctivecognitive function in older adults associated with
bilobed leaves of Ginkgo biloba trees have beenGinkgo biloba supplements, there may still be potential
found on multiple continents, modern day Gingkoclinical applications for this ancient herbal remedy in
trees now grow naturally only in China (although theyview of its known ability to improve blood flow
have been widely cultivated, over a period ofthrough networks of small blood vessels in the body.
centuries, throughout Asia, and particularly in JapanThere is also some research evidence available
and Korea).suggesting that Ginkgo biloba may have potentially
A new highly-powered prospective clinical researchimportant anti-inflammatory properties, and that
trial evaluating Ginkgo biloba supplementation appearsthese properties might be clinically useful in some
in this week's issue of the Journal of the Americanchronic inflammatory diseases, such as ulcerative
Medical Association. More than 3,000 adults betweencolitis (Ginkgo biloba, ulcerative colitis & colorectal
the ages of 72 and 96 years participated in thiscancer). For now, however, the overwhelming
placebo-controlled research trial, with an impressiveavailable clinical research evidence indicates that
average patient follow-up duration of more than 6Ginkgo biloba appears to offer no benefit to older
years. These patient volunteers were secretlypatients in terms of either preserving or improving
randomized to one of two groups. The patients inmemory, or in improving other areas of higher
the "experimental group" received 120 mg of Ginkgocognitive function.
biloba extract twice daily during the course of this