HEALTH SERVICE RESEARCH POSTER PRESENTATION ABSTRACTS
Please note: All posters will be displayed in
Salons 10-12.
FRIDAY, 10:15-11:00 AM
Buettner C, Yeh GY, Phillips RS, Mittleman MA, Kaptchuk
TJ.
Systematic review of the effects of ginseng on cardiovascular
risk factors.
Harvard Medical School, Osher Institute catherine_buettner@hms.harvard.edu
PURPOSE: We sought to examine the evidence for
efficacy of ginseng (Panax species) on cardiovascular risk factors,
including blood pressure, lipid profiles, and blood glucose.
METHODS: We searched MEDLINE, AMED, BIOSIS,
CAB, EMBASE and the Cochrane Controlled Trials databases from inception
through July 2005 and performed hand searches of bibliographies. We
included both randomized controlled trials (RCTs) and non-randomized
studies (NRSs) published in English. Data were extracted in a standardized
manner, and two independent investigators assessed methodological quality
of the studies.
RESULTS: We identified 34 studies with results
for blood pressure, lipids, and/or blood glucose. The majority of studies
were ² 12 weeks and included < 30 subjects. Effects on blood pressure
were examined in 12 studies and seven demonstrated slight reductions
(0.5-5%) in systolic blood pressure and/or diastolic blood pressure
compared to placebo or control. However, only three of these differences
were statistically significant (p<0.05). Two NRSs showed significant
reductions (8-11%) after a single ginseng dose compared to baseline.
Three studies demonstrated slight elevations in blood pressure (1-4%),
which were not statistically significant. We found mixed results for
an effect on lipids. Out of nine studies, five NRSs showed improvement
in one or more lipid parameter compared to baseline (range 7-44%), but
no RCT showed significant differences. Fifteen studies examined blood
glucose lowering effects. Four out of six studies conducted over 3 days
to 12 weeks demonstrated significant reductions in blood glucose (7-13%)
and/or hemaglobinA1C (4-10%). Nine studies were performed as acute single-dose
studies carried out by one group. Of these nine studies, five were performed
using ginseng from one batch and demonstrated significant decreases
in postprandial blood glucose (9%-39%, area under the curve analysis).
Use of a different batch of ginseng (from the same manufacturer) or
use of a different ginseng variety demonstrated either no change in
blood glucose or increased postprandial blood glucose. The methodological
quality of most studies was judged to be poor.
CONCLUSIONS: Current evidence does not support
the use of ginseng to reduce cardiovascular risk factors. There is no
consistent evidence that ginseng lowers or increases blood pressure.
Preliminary non-randomized studies suggest ginseng may have an effect
on improving lipid profiles, however randomized placebo-controlled studies
designed to evaluate the effect of ginseng on lipids as a primary outcome
are lacking. Despite evidence showing an effect of ginseng on lowering
blood glucose, results are inconsistent and may be dependent on the
ginseng preparation and batch of ginseng evaluated.
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