Ginkgo Biloba Improves Recall for
Senior Citizens
Although all volunteers taking gingko biloba experienced better verbal recall, a
larger sample size may be needed to effectively track brain metabolism
Nov.
10, 2003 - Seniors citizens and Baby Boomers with memory problems who
took ginkgo biloba experienced significant improvement in verbal recall,
according to a UCLA study.
UCLA
Neuropsychiatric Institute researchers found this recall improvement
among a group of people with age-associated memory impairment who took
the herbal supplement ginkgo biloba for six months compared with a group
who took a placebo.
The
UCLA study, released today at the Society for Neuroscience 2003 Annual
Meeting, being held Nov. 8-12 in New Orleans, used positron emission
tomography (PET) and found that for subjects taking gingko, improved
recall correlated with better brain function in key brain memory
centers.
However, actual changes in brain metabolism, measured by PET for the
first time, did not differ significantly between the two volunteer
groups. Researchers noted that although all volunteers taking gingko
biloba experienced better verbal recall, a larger sample size may be
needed to effectively track brain metabolism results.
Our
findings suggest intriguing avenues for future study, including using
PET with a larger sample to better measure and understand the impact of
gingko biloba on brain metabolism, said Dr. Linda Ercoli, lead study
author and assistant clinical professor at the UCLA Neuropsychiatric
Institute.
Gingko biloba is a Chinese herb often used to treat memory loss as a
dietary supplement. The effect of ginkgo biloba on brain metabolism,
which has never been measured until now, and previous controlled
clinical trials on the supplements effects on verbal recall have
yielded conflicting results.
The
research also raises questions regarding the significance of supplement
quality and treatment duration, said principal investigator Dr. Gary
Small, Parlow-Solomon Professor of Aging and professor at the UCLA
Neuropsychiatric Institute. The Food and Drug Administration does not
regulate dietary supplements, and the quality of retail supplies vary
widely. We used only the highest grade of ginkgo biloba in conducting
our research.
Small also noted that the UCLA study is one of the first to measure the
effects of gingko biloba over a longer period of time six months. Most
previous studies have measured the effect of the supplement over 12
weeks or less.
The
study examined the impact of ginkgo biloba compared to a placebo in 10
patients, ages 45-75, who did not have dementia but only mild
age-related memory complaints. Four subjects received 120 mg of ginkgo
biloba twice daily and six received a placebo, or inactive substance
such as a sugar pill.
Researchers used cognitive tests to measure verbal recall and PET to
measure brain metabolism before and after the treatment regimen.
Magnetic resonance imaging was used to determine regions of interest to
be examined by PET.
Study funding was provided by Dr. Willmar Schwabe GmbH & Co., John
Douglas French Alzheimers Foundation, the Louis and Harold Price
Foundation, the Larry L. Hillblom Foundation, and the UCLA Center on
Aging.
The
UCLA Neuropsychiatric Institute is an interdisciplinary research and
education institute devoted to the understanding of complex human
behavior, including the genetic, biological, behavioral and
sociocultural underpinnings of normal behavior, and the causes and
consequences of neurophychiatric disorders. More information is
available online at www.npi.ucla.edu.
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