in der vom Hersteller typischerweise empfohlenen Dosierung eingenommen,
so sind sie in Hinsicht auf die Gedächtnisleistung unwirksam.
Ginkgo for Memory Enhancement - A Randomized
R. Solomon, PhD; Felicity Adams, BA; Amanda Silver, BA; Jill Zimmer,
BA; Richard DeVeaux, PhD
over-the-counter treatments are marketed as having the ability
to improve memory, attention, and related cognitive functions
in as little as 4 weeks. These claims, however, are generally
not supported by well-controlled clinical studies.
evaluate whether ginkgo, an over-the-counter agent marketed as
enhancing memory, improves memory in elderly adults as measured
by objective neuropsychological tests and subjective ratings.
randomized, double-blind, placebo-controlled, parallel-group trial.
and Participants Community-dwelling volunteer men
(n = 98) and women (n = 132) older than 60 years with Mini-Mental
State Examination scores greater than 26 and in generally good
health were recruited by a US academic center via newspaper advertisements
and enrolled over a 26-month period from July 1996 to September
were randomly assigned to receive ginkgo, 40 mg 3 times per day
(n = 115), or matching placebo (n = 115).
Outcome Measures Standardized neuropsychological
tests of verbal and nonverbal learning and memory, attention and
concentration, naming and expressive language, participant self-report
on a memory questionnaire, and caregiver clinical global impression
of change as completed by a companion.
hundred three participants (88%) completed the protocol. Analysis
of the modified intent-to-treat population (all 219 participants
returning for evaluation) indicated that there were no significant
differences between treatment groups on any outcome measure. Analysis
of the fully evaluable population (the 203 who complied with treatment
and returned for evaluation) also indicated no significant differences
for any outcome measure.
results of this 6-week study indicate that ginkgo did not facilitate
performance on standard neuropsychological tests of learning,
memory, attention, and concentration or naming and verbal fluency
in elderly adults without cognitive impairment. The ginkgo group
also did not differ from the control group in terms of self-reported
memory function or global rating by spouses, friends, and relatives.
These data suggest that when taken following the manufacturer's
instructions, ginkgo provides no measurable benefit in memory
or related cognitive function to adults with healthy cognitive
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Author Affiliations: Department of Psychology (Dr Solomon
and Ms Zimmer), Program in Neuroscience (Dr Solomon and Mss Adams,
Silver, and Zimmer), Department of Mathematics and Statistics
(Dr DeVeaux), Williams College, Williamstown, Mass; and The Memory
Clinic, Southwestern Vermont Medical Center, Bennington (Dr Solomon).
Corresponding Author and Reprints: Paul R. Solomon, PhD,
Bronfman Science Center, Williams College, 33 Hoxsey St, Williamstown,
MA 01267 (e-mail: firstname.lastname@example.org).
Contributions: Study concept and design: Solomon, Silver.
of data: Solomon, Adams, Silver, Zimmer.
and interpretation of data: Solomon, DeVeaux.
of the manuscript: Solomon.
revision of the manuscript for important intellectual content:
Solomon, Adams, Silver, Zimmer, DeVeaux.
expertise: Solomon, DeVeaux.
technical, or material support: Adams, Silver, Zimmer.
This work was supported by grants from the National Institute
on Aging (AGO-5134-08S2), the Howard Hughes Medical Foundation,
and the Essel Foundation.