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- Ginkgo (Ginkgo biloba)
- Cognitive Decline
- Long-tern Effects
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Date:
07-31-2013 | HC# 031356-477
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Re: Ginkgo Use Reduces Long-term Cognitive Decline in Elderly without Dementia
Amieva
H, Meillon C, Helmer C, Barberger-Gateau P, Dartigues JF. Ginkgo biloba extract and long-term cognitive decline: A 20-year
follow-up population-based study. PLoS One.
2013;8(1):e52755. doi: 10.1371/journal.pone.0052755.
Ginkgo
(Ginkgo biloba) is used to treat
patients with mild cognitive impairment or dementia. Reviews and meta-analyses
conclude that the ginkgo leaf extract EGb 761® (Dr. Willmar Schwabe
Pharmaceuticals; Karlsruhe, Germany) is effective in the symptomatic treatment
of patients with dementia. A couple of large-scale clinical trials (> 2800
participants) failed to show efficacy in preventing the development of dementia
in healthy, elderly people. This exploratory retrospective analyses of data
from a prospective study evaluates the efficacy of ginkgo in a study of 3612 subjects
who were followed for 20 years.
This
paper reports on a retrospective analysis of data collected prospectively over
20 years as part of the PAQUID (personnes âgées quid) cohort. The PAQUID study
is a population-based study conducted in Gironde and Dordogne, France, which has
completed 20 years of follow-up. This makes it one of the largest and
longest-running prospective studies evaluating the natural history of cognitive
decline and incidence of dementia. The PAQUID study originally enrolled 3777
people aged ≥ 65 years representing the community. Data were collected by means
of a questionnaire administered at home by trained psychologists at inclusion
and after 1, 3, 5, 8, 10, 13, 15, 17, and 20 years. The questionnaire included an
evaluation of mental status via the mini-mental state exam (MMSE), the Benton
Visual Retention Test (BVRT), the Isaacs Set Test (IST), and an assessment of
dementia according to the Diagnostic and
Statistical Manual of Mental Disorders (DSM-III-R)
criteria. Participants in PAQUID who were diagnosed with dementia at study
inclusion (n = 102) were not included in this retrospective analysis. The
included subjects were separated into the 3 following groups: (1) subjects
reporting use of EGb 761 (e.g., Tanakan®; Ipsen; Paris, France; Tebonin®;
Dr. Willmar Schwabe Pharmaceuticals) at any visit (n = 589), (2) subjects
reporting use of piracetam at any visit (n = 149), and (3) subjects not
reporting use of either EGb 761 or piracetam (n = 2874). Those using both EGb 761
and piracetam at any time (n = 63) were also excluded from the analysis.
At
baseline, the groups did not differ in age or number of medications consumed. Also
at baseline, subjects taking "neither treatment" were more frequently
men, less educated, and had fewer memory complaints. Subjects using EGb 761
were more frequently women and less frequently reported depressive symptoms or
memory complaints compared to subjects taking piracetam. Baseline MMSE scores
were slightly higher in the EGb 761 group. At 20 years, 73.3% of the EGb 761
group, 86.6% of the piracetam group, and 81.3% of the control group had died.
Subjects
using EGb 761 had a rate of MMSE decline that was significantly less rapid than
the "neither treatment" group (P < 0.0001). The mean difference in
the MMSE score at 20 years was 5 points, which is considered clinically
relevant. The piracetam group declined more rapidly than the "neither
treatment" group. On the IST and BVRT, there was no significant difference
in the rate of decline between the EGb 761 and "neither treatment"
groups, whereas the piracetam group declined more rapidly. The differences in
cognitive decline between groups did not change after controlling for
psychotropic drug use (antidepressants, benzodiazepines, and antipsychotics).
The
authors conclude that non-demented subjects who used EGb 761 had a slower rate
of cognitive decline as measured with the MMSE than untreated subjects or
subjects treated with piracetam. The clinical benefit of EGb 761 was only apparent
after several years. The study shows that cognitive decline in elderly,
non-demented subjects is a slow process. Therefore, it is possible that other
studies that have reported that ginkgo was not beneficial for the prevention of
cognitive decline did not have a duration of sufficient length (they were 3.5
to 6 years in duration). The authors state that firm conclusions should not be
drawn from the piracetam results because the population size was too small.
The
limitations of this study are that the dose and duration of EGb 761 treatment were
not controlled. In addition, treatments were self-selected and had differing
characteristics at baseline. Therefore, conclusions cannot be drawn regarding
optimal dosage or when to initiate treatment. Nonetheless, the study suggests a
possible effect of ginkgo in a real-world setting.
—Heather S. Oliff,
PhD
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