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- Rhodiola (Rhodiola rosea)
- Fatigue
- Stress
| Date:
07-29-2011 | HC#
041162-429
|
Re: Human Studies on Rhodiola Show Enhanced Physical and Mental Functions
Hung
SK, Perry R, Ernst E. The effectiveness and efficacy of Rhodiola rosea L.: a systematic review of randomized clinical
trials. Phytomedicine. February 15, 2011;18(4):235-244.
Rhodiola
(Rhodiola rosea) is found at high
altitudes in Europe and Asia and has traditionally been used in Russia, Scandinavia,
and eastern Europe for combating high altitude sickness, depression, fatigue,
and for nervous system stimulation. Rhodiola is reported to influence
monoamines and opioid peptides, and has been found to contain compounds unique to
this species.1,2 Although the bioactivity of this plant is diverse,
the authors point to a dearth of review articles on its efficacy and set out to
summarize the methodology and results of randomized clinical trials (RCTs) of rhodiola.
To
identify RCTs for the review, the authors searched AMED from 1985-July 2009,
CINAHL from 1982-July 2009, The Cochrane Library in July 2009, EMBASE from
1974-July 2009, MEDLINE from 1950-July 2009 and Web of Science in July 2009.
They employed the words or phrases "R.
rosea," "SHR-5," "golden radix," "rhodiola,"
"arctic root," "Aaron rod," "roseroot,"
"rosavin," "rosin," "rosarin,"
"rhodaz," "Vitano," and "Hong Jian Tian." The
authors also searched the references of all literature obtained to identify
additional RCTs and inquired with rhodiola manufacturers and herbal medicine
professionals to find any overlooked or unpublished material. The authors
included all material regardless of language of publication.
The
authors included only RCTs that investigated rhodiola as a single preparation
used as an oral treatment alongside a control group with either ill patients or
healthy subjects. Control group criteria included either a placebo, no
treatment, or an active treatment. Studies that used rhodiola in combination
with other treatments were excluded. The authors gathered the study design,
study quality, number of participants, intervention, results, and adverse
events. Each study was assessed using the Jadad score for methodological
quality, with additional assessment taken from The Cochrane Handbook of
Systematic Reviews of Interventions, used for standardizing healthcare
interventions, and the CONSORT statement of herbal medicine. [The CONSORT
statement of 15 criteria for clinical trials involving herbal medicine is
conveniently included as an appendix]. The type and appropriateness of sequence
generation, allocation adequately concealed, whether intention to treat
analysis was conducted and described, matching of groups at baseline, and the 15
items in the CONSORT statement were used to assess each RCT.
The
literature searches yielded 693 candidates for further screening. Of these, 11
RCTs met all the inclusion criteria. In summary, the studies were published
between 2000 and 2009 and were from Russia, Armenia, the USA, Sweden, Belgium,
and the Netherlands. Although one study did not report the number of subjects,
there was a wide range of participants in the included RCTs (n=12-121) for a
total of 503 in the other 10. Eight of the studies were conducted on healthy
subjects exposed to hypoxia, fatigue, or stress from exercise, work, or exams
and one RCT investigated subjects for alterations of photon emission, stress,
and fatigue. The two remaining trials focused on patients with stress-related
fatigue and mild to moderate depression. All RCTs included a placebo.
The
authors separated the studies into 7 investigations of physical performance and
its physiological indicators, 4 on mental performance, and 2 for mental health
conditions. Parameters reported in the RCTs of physical performance ranged from
physical performance itself and exhaustion levels, to blood oxygenation in
hypoxia conditions. Two of the RCTs (n=15 and n=12) reported that rhodiola
failed to improve blood oxygenation after hypoxia was induced or to increase
skeletal muscle phosphocreatine recovery after exercise. In contrast, other
studies reported a significant increase in time to exhaustion, mean C-reactive
protein levels, and neuromotoric fitness in the rhodiola treatment groups
(P<0.005). Another study also found that rhodiola improved tiredness
perception (P=0.049).
The
measurements used in the mental performance RCTs were short term memory,
reaction time to various stimuli, and concentration. Two of these studies
observed significant improvements in Total Antifatigue Index and Total Fatigue
Index scores of the rhodiola treatment groups in comparison with the placebo
(P<0.05).
In
the RCTs examining mental health, fatigue syndrome and depression were
analyzed. The rhodiola-treated patients with stress-related fatigue improved
significantly over the placebo group (P=0.047). In addition, patients suffering
from depression significantly improved when treated with rhodiola as compared
to the placebo group (P<0.0001), according to the Hamilton Rating Scale for
Depression and the Beck Depression Inventory, commonly used questionnaires for
rating the severity of depression symptoms. Of the 11 RCTs in this analysis,
eight of them assessed adverse effects and only three were reported including
headache and hypersalivation, both from the placebo group. Although the trials
did not describe these as serious, an unexplained illness caused one patient to
drop out of the study.
According
to the authors' assessment, five studies had good methodological quality with a
Jadad score of three points or higher. Four studies had a score of two points
or lower, and the authors mention that seven RCTs failed to clearly state their
intention to treat analyses. The authors noted that, with possibly one
exception, the studies did not adequately report on the preparations of rhodiola
utilized.
The
authors conclude that rhodiola may be active in a variety of ways and might be
used to treat several ailments, including those brought on by stress and
depression. However, they do point out that they may have overlooked certain
RCTs, and the studies included in this review have not been replicated.
This
review is thorough and balanced, and the authors make excellent use of
quantitative assessment to evaluate the RCTs involving rhodiola. The authors
themselves conclude that the reported bioactivity of rhodiola warrants further
investigation; this review outlines a convincing argument for this
conclusion.
—Amy C.
Keller, PhD
References
1Webb D. Rhodiola rosea as a plant adaptogen. HerbClip. November 14, 2002 (No.
100411-220). Austin, TX: American Botanical Council. Review of Rhodiola rosea: a possible plant
adaptogen by Kelly GS. Altern Med Rev.
2001;6(3):293-302.
2Oliff HS. Rhodiola
rosea monograph in HerbalGram. HerbClip. December 31, 2003 (No.
070336-247). Austin, TX: American Botanical Council. Review of Rhodiola rosea: a phytomedicinal overview
by Brown RP, Gerbarg PL, Ramazanov Z. HerbalGram.
2002;(56):40-52.
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