Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials.
PubMed 36017529 · doi:10.1002/ptr.7598
What was done
Authors conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) indexed in PubMed/Medline, Scopus, and Google Scholar from inception through December 2021. Eligible studies evaluated the effect of Ashwagandha extract versus placebo on anxiety and stress outcomes in adults. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were pooled using a random-effects model alongside non-linear dose-response analyses.
What was found
Twelve studies comprising 1,002 participants (aged 25 to 48 years) were included. Ashwagandha supplementation significantly reduced anxiety (SMD: -1.55, 95% CI: -2.37 to -0.74; p = .005; I² = 93.8%) and stress levels (SMD: -1.75; 95% CI: -2.29 to -1.22; p = .005; I² = 83.1%) compared to placebo. Dose-response modeling indicated favorable effects on anxiety up to 12,000 mg/day and on stress at 300 to 600 mg/day. Certainty of evidence was rated as low for both outcomes.
Why it matters
This review aggregates randomized trial data showing that ashwagandha extract reduces self-reported stress and anxiety across several dosing regimens. It provides quantitative summary estimates while highlighting substantial variability in the current literature.
Limits
Statistical heterogeneity was extremely high for both anxiety (I² = 93.8%) and stress (I² = 83.1%), and the certainty of evidence for both outcomes was rated as low. The total sample size across 12 trials was relatively small (1,002 participants), participants were limited to ages 25 to 48 years, and specific extract formulations and trial quality varied.
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