| FOR IMMEDIATE RELEASE
CONTACT: Robert S. McCaleb
Negative Ginkgo Study Does Not Negate Strong Body of Positive
October 5, 2000: Reuters Health Newswire released a story
today publicizing a well-controlled Dutch study showing that ginkgo
had no effect on age-related memory loss. This negative study
has not yet received significant media attention, which is appropriate
in light of the abundance of evidence showing a memory-enhancing
effect for ginkgo. To put the new study in perspective, HRF wishes
to stress that no matter how dramatic - or unimpressive - the
results of a single clinical trial are, they must always be considered
in light of existing good-quality research.
To summarize the double-blind, randomized, placebo-controlled
study, 214 elderly subjects with dementia or Alzheimer's disease
took ginkgo or placebo for 12 or 24 weeks. The researchers used
neuropsychological tests, clinical assessments, and behavioral
self-assessments as outcome measures, but observed no ginkgo effect.
The negative results of the Dutch trial must be weighed against
the conclusions of previously published studies - which, taken
together, show that ginkgo had a significantly beneficial effect
on mental function for tens of thousands of elderly people
with age-related memory decline, Alzheimer's disease, or multi-infarct
dementia. While this study was accepted for publication in a peer-reviewed
journal, so were most of the trials that support gingko's efficacy
in treating these conditions.
The scientific literature for even the best-respected remedies
contains contradictory findings. As any scientist knows, mixed
results can provide patterns that help us refine our theories.
For example, most ginkgo studies show no observable effect without
at least four weeks of treatment - yet a handful of recent studies
in humans and rats have shown that a single large dose
of ginkgo can improve reaction time for several hours afterward.
Although a new contradictory result is always interesting, it
by no means negates the body of clinical research that has come
before it. View an abstract of the Dutch study at www.amgeriatrics.com,
volume 48, issue 10.
van Dongen M, van Rossum E, Kessels AGH, et al. The efficacy of
ginkgo for elderly people with dementia and age-associated memory
impairment: new results of a randomized clinical trial. Journal
of the American Geriatrics Society 2000; 48: 1183-94.