Ginkgo Biloba Does Not Appear To Prevent Dementia,
Alzheimer's Disease in Elderly
The rate of total dementia did not differ between
seniors assigned to Ginkgo biloba vs. placebo
Nov. 18, 2008 - The herb Ginkgo biloba has been
aggressively marketed to senior citizens around the world as a way to
improve memory and even prevent dementia. A new study, however, says the
herb is not effective in reducing the rate of dementia or Alzheimers
disease among senior citizens age 75 or older.
$4 billion a year spent on herbal products for
better health, memory, sex
April 25, 2007 Senior citizens, probably the most
ardent seekers of better health, are among the Americans that consume
more than $4 billion worth of St. Johns wort, echinacea, Ginkgo biloba
and other herbal products each year in hopes of improving their health,
memory and even their sex lives. A major conference opens next week at
the University of Mississippi to explore the latest studies on the
safety and quality of botanical dietary supplements.
Read
more, link to video...
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. Read More...
The study, reported in the November 19 issue of the
Journal of the American Medical Association (JAMA), tested Ginkgo
biloba with 1,500 senior citizens over several years.
Dementia, especially Alzheimer's disease (AD), is a
prevalent chronic disease currently affecting more than 5 million people
in the United States and is a leading cause of age-related disability
and long-term care placement, according to background information in the
article.
Ginkgo biloba is prescribed in some areas of the
world for preservation of memory; however, there are no medications
approved for prevention of dementia, and to date, no clinical trial of
adequate design and size has evaluated the safety and effectiveness of
Ginkgo biloba in the primary prevention of dementia.
Steven T. DeKosky, M.D., of the University of
Pittsburgh, Pa., at the time of the study, and the Ginkgo Evaluation of
Memory (GEM) Study Investigators, assessed the effectiveness of Ginkgo
biloba in dementia prevention.
The study was a randomized, placebo-controlled
clinical trial conducted at five academic medical centers in the United
States between 2000 and 2008 with a median (midpoint) follow-up of 6.1
years.
About Ginkgo
The
ginkgo tree is one of the oldest types of trees in the world.
Ginkgo seeds have been used in traditional Chinese medicine for
thousands of years, and cooked seeds are occasionally eaten.
Common Names - ginkgo,
Ginkgo biloba, fossil tree, maidenhair tree, Japanese silver
apricot, baiguo, bai guo ye, kew tree, yinhsing (yin-hsing)
Latin Name - Ginkgo biloba
What It Is Used For
● Ginkgo leaf extract has
been used to treat a variety of ailments and conditions,
including asthma, bronchitis, fatigue, and tinnitus (ringing or
roaring sounds in the ears).
● Today, people use ginkgo
leaf extracts hoping to improve memory; to treat or help prevent
Alzheimer's disease and other types of dementia; to decrease
intermittent claudication (leg pain caused by narrowing
arteries); and to treat sexual dysfunction, multiple sclerosis,
tinnitus, and other health conditions.
The trial included 3,069 community volunteers age
75 years or older with normal cognition (2,587 participants) or mild
cognitive impairment (MCI) (482 participants) at study entry, who were
assessed every 6 months for dementia. Participants were randomized to
receive either a twice-daily dose of 120-mg extract of Ginkgo biloba
(1,545 people) or placebo (1,524 people).
The researchers found that during the intervention
period, 523 participants were diagnosed with dementia - 246 (16.1
percent) in the placebo group and 277 (17.9 percent) in the Ginkgo
biloba group.
Of the total dementia cases, 92 percent were
classified as possible or probable AD, or AD with evidence of vascular
disease of the brain.
The rate of total dementia did not differ between
participants assigned to Ginkgo biloba vs. placebo:
● 3.3 dementia cases per100 persons, per year exposed, among persons
randomized to Ginkgo biloba;
● 2.9 per 100 persons, per year exposed, among persons randomized to
placebo.
The rate of Alzheimer-type dementia also did not
differ between the two treatment groups (3.0 per 100 persons, per year
exposed vs. 2.6 per 100 persons, per year exposed).
Ginkgo biloba also had no effect on the rate of
progression to dementia in participants with MCI.
The adverse event profiles for Ginkgo biloba and
placebo were similar and there were no statistically significant
differences in the rate of serious adverse events.
"Based on the results of this trial, Ginkgo biloba
cannot be recommended for the purpose of preventing dementia," the
authors write.
"These results confirm that randomized trials
remain critical to the spectrum of translational research necessary to
develop new therapies and to determine whether the purported in-vitro,
epidemiologic, and surrogate measures of therapeutic benefit are true
not only for traditional pharmaceutical therapies but also for
complementary therapies.
"Of almost equal importance from these results
is the provision of a strong rationale for including older individuals
in randomized trials testing promising interventions for preventing or
delaying dementia onset."
Editorial: Ginkgo biloba extract and
preventing Alzheimer disease
In an accompanying editorial, Lon S. Schneider,
M.D., of the University of Southern California, Los Angeles, comments on
the findings of DeKosky and colleagues.
"Despite 2 decades of research with standardized
extracts of Ginkgo biloba, considerable uncertainty about its
pharmacology and clinical effects remains.
Preclinical scientific reports exude promise but
generally have not identified the relevant active molecules of this
biochemically complex extract, and the preclinical promise has not
translated to clinical research benefits.
The clinical research, in turn, has not adequately
defined potential cognitive indications, potentially effective dosing
ranges, pharmacodynamic markers, or convincing evidence for efficacy for
any one cognitive condition.
The GEM study adds to the substantial body of
evidence that Ginkgo biloba extract as it is generally used does not
prevent dementia in individuals with or without cognitive impairment and
is not effective for Alzheimer disease."
Editor's Note: Dr. DeKosky is now with the
University of Virginia School of Medicine, Charlottesville.
Keep up with the latest news for senior citizens, baby
boomers
Nov. 18, 2008 - The herb Ginkgo biloba has been
aggressively marketed to senior citizens around the world as a way to
improve memory and even prevent dementia. A new study, however, says the
herb is not effective in reducing the rate of dementia or Alzheimers
disease among senior citizens age 75 or older.