PDF
(Download)
|
- Ashwagandha (Withania somnifera, Solanaceae)
- Stress and Anxiety
- Safety and Efficacy
|
Date:
08-31-2016 | HC# 021652-551
|
Re: Ashwagandha Reduces Perceived Stress and Cortisol Levels in Healthy Adults
Chandrasekhar
K, Kapoor J, Anishetty S. A prospective, randomized double-blind,
placebo-controlled study of safety and efficacy of a high-concentration
full-spectrum extract of ashwagandha root in reducing stress and anxiety in
adults. Indian J Psychol Med.
2012;34(3):255-262.
Ashwagandha
(Withania somnifera, Solanaceae) root
is an adaptogen, which is a substance that helps the body cope with stress. This
study was published in 2012, and the authors state that at that time clinical
trials evaluating ashwagandha for the treatment of stress and anxiety were
limited. Hence, the purpose of this prospective, randomized, double-blind,
placebo-controlled study was to evaluate the safety and efficacy of a
full-spectrum extract of ashwagandha root in reducing stress and anxiety in
healthy adults.
Subjects
(n = 64; aged 18-54 years) with a history of chronic stress participated in
this study conducted at Asha Hospital; Hyderabad, India. The subjects were "a
wide cross-section of the population, which included doctors, students,
self-employed persons, executives and employees of information technology
firms," who attended a stress-management talk. Included subjects had no
psychiatric conditions other than stress, < 15 points on the World Health Organization-5
well-being index (WHO-5), and ≥ 14 points on the Perceived Stress Scale (PSS).
Excluded subjects had any chronic physical, hormonal, or psychiatric illness; were
using "certain" hormonal birth control; were taking any medication on
a regular basis; were taking any herbal preparations or formulations containing
ashwagandha, ginseng (Panax spp.,
Araliaceae) root, ginkgo (Ginkgo biloba,
Ginkgoaceae) leaf, bacopa (brahmi; Bacopa
monnieri, Plantaginaceae) aerial plant parts, or related herbs; were pregnant
or lactating; had substance dependence; or had abnormal laboratory or electrocardiogram
(ECG) test results.
Subjects
(41 males and 23 females) were randomly assigned to receive placebo ("capsules
containing a neutral substance") or 600 mg/day ashwagandha root extract
(KSM-66® ashwagandha extract; Ixoreal Biomed; Hyderabad, India) for
60 days. The extract "is produced by a unique extraction process, based on
the principles of 'green chemistry', without using alcohol or any synthetic
solvents," and standardized to contain at least 5% withanolide. The effect
of ashwagandha on stress was evaluated by assessing (at baseline and day 60) serum
cortisol levels and scores on the PSS questionnaire, the Depression Anxiety
Stress Scale (DASS) questionnaire, and the 28-item version of the General
Health Questionnaire (GHQ-28). Safety of the ashwagandha extract was assessed
based on laboratory findings and incidence of adverse events (AEs).
A
total of 61 subjects completed the trial; an accounting of the dropouts was not
given. Compliance data was not reported.
At
baseline, the mean score for self-perceived stress on the PSS was classified as
"moderate" for both groups; however, the mean score was significantly
higher in the placebo group (P = 0.009). At study end, the ashwagandha group
had a significantly greater reduction in total PSS score compared with the
placebo group (P < 0.0001). It is not clear whether the higher score for the
placebo group at baseline had an impact on the outcome.
There
was no significant difference between groups in GHQ-28 or DASS scores. At study
end, the ashwagandha group had a significantly greater reduction in GHQ-28 total
score and each item-subset score (somatic, anxiety and insomnia, social
dysfunction, and severe depression) compared with placebo (P ≤ 0.0001 for all).
Similarly, the ashwagandha group had a significantly greater reduction in the DASS
total score and each item-subset score (depression, anxiety, and stress) compared
with placebo (P < 0.0001 for all).
A
strength of this study is that the 3 instruments used to assess self-perceived stress
were all ratio scales (based on the frequency of stress-signaling events, with
a score of 0 indicating a total absence of events). Therefore, each score may
be interpreted as the absolute degree of self-assessed stress.
Cortisol
is used as a biological marker of stress, and as such, provides an objective
measure of stress. At study end, the ashwagandha group had a significantly
greater reduction in cortisol levels compared with the placebo group (P =
0.002).
AEs
were mild, infrequent, and considered unrelated to treatment; there was no
significant difference in the incidence of AEs between groups. There were no clinically
significant changes in laboratory parameters.
The
authors conclude that this specific full-spectrum ashwagandha root extract can safely
improve resistance to stress, and as a result, improve self-assessed quality-of-life
measures. Strengths of the study are the use of 3 instruments to measure
self-assessed stress, the evaluation of cortisol levels to provide an objective
measure of stress, and that the treatment was evaluated under real-world
conditions rather than artificially induced experimental stress. Limitations of
the study were the relatively small population size (n = 32/group), the relatively
short duration, that 64% of the population were men, and that compliance,
dropout, and full demographic data were not provided. The study should be
repeated in a larger, gender-balanced population for a longer period of time.
—Heather S. Oliff,
PhD
|