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Red Ginseng
Shows Mild Blood Pressure-Lowering Effect
The effects of Asian ginseng (Panax
ginseng C.A. Meyer, Araliaceae) on blood pressure are controversial,
and the few clinical studies conducted in this area have yielded
conflicting results. To shed light on the issue, a group of Korean
researchers designed a small placebo-controlled study to examine
the effects of red ginseng in people with mild or moderate hypertension
(Han et al., 2000). While earlier studies based evaluations
on single blood pressure measurements taken in clinics, these
investigators used 24-hour ambulatory blood pressure monitoring
(ABPM) in an attempt to avoid potentially confounding effects
related to clinic-based measurements. ABPM records 50 readings
per 24-hour measurement period, and thus may be expected to allow
more accurate assessment of actual blood pressure changes.
The 34 study participants were categorized
as having either essential or "white coat" hypertension. Although
not specifically defined by the authors of this study, the term
"white coat hypertension" is typically used to describe a transient
rise in blood pressure associated with clinical settings. In this
study, these were people whose initial clinic-based diastolic
blood pressure was above 90 mmHG and below 110 mmHG, but below
90 mmHG according to 24-hour mean ABPM.
Essential hypertension (also known as primary
or idiopathic hypertension) is high blood pressure with no apparent
cause. Mild or moderate essential hypertension in this study was
defined as blood pressure over 140/90 mmHG, with diastolic blood
pressure lower than 110 mmHG. The
essential hypertension group was subdivided into three treatment
subgroups, two of which received pharmaceutical blood pressure
medications (beta blockers or calcium channel blockers) in addition
to ginseng.
After an initial four weeks of treatment
with placebo, the study participants took 1.5 g of red ginseng
three times a day (a total daily dose of 4.5 g) for eight weeks.
Blood pressure was measured via ABPM at baseline, after the four-week
placebo period, and again after eight weeks of treatment with
red ginseng. Each time, blood pressure was recorded at 30-minute
intervals for 24 hours. In the 26 participants with essential
hypertension, the researchers observed a significant drop in 24-hour
mean systolic blood pressure, but only a tendency toward decline
in diastolic blood pressure. The degree of decline in systolic
blood pressure was calculated at about 5 percent. The investigators
deemed the reduction a significant effect of ginseng treatment
"regardless of other medications taking [sic] in addition to red
ginseng." No changes were seen in the eight patients with white
coat hypertension. They concluded, "Mild decrease in systolic
and diastolic blood pressure was observed without serious side
effects and discomfort due to red ginseng medication in idiopathic
hypertensive patients."
"Red" ginseng is produced by steaming or
otherwise processing fresh, unprocessed "white" ginseng root.
The red ginseng used in the study was supplied by Korean Tobacco
& Ginseng Corporation of Taejeon, Korea. Each unstandardized capsule
was reported to contain 300 mg of ginseng.
- Evelyn Leigh, Herb Research Foundation
[Han KH, Choe SC, Kim HS, Sohn DW, Nam KY, Oh HB, Lee MM, Park
YB, Choi YS, Seo JD, Lee YW. Effect of red ginseng on blood pressure
in patients with essential hypertension and white coat hypertension.
American Journal of Chinese Medicine 1998; 26(2): 199-209.]
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