A combination of green tea, rhodiola, magnesium and B vitamins modulates brain activity and protects against the effects of induced social stress in healthy volunteers.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 33896388 · doi:10.1080/1028415X.2021.1909204
What was done
In a double-blind, randomized, placebo-controlled, parallel-group trial, 100 moderately stressed adult volunteers were randomized to one of four acute oral supplementation arms: (1) magnesium + B vitamins + green tea + rhodiola; (2) magnesium + B vitamins + rhodiola; (3) magnesium + B vitamins + green tea; or (4) placebo. Following supplementation, participants underwent the Trier Social Stress Test (TSST). Evaluated endpoints included resting-state EEG alpha and theta oscillations, subjective mood and stress states, blood pressure, heart rate variability, and salivary cortisol responses.
What was found
The abstract provides p-values but no baseline or post-treatment numerical values. The full combination supplement significantly increased resting-state EEG theta activity compared to control (p < .02). The combination also attenuated subjective stress, anxiety, and general mood disturbance, while heightening subjective and autonomic arousal (p < .05). Specific results for the two partial combination arms, cortisol, blood pressure, and heart rate variability are not reported with numbers in the abstract.
Why it matters
This trial suggests that combining magnesium and B vitamins with botanical extracts (green tea and rhodiola) may acutely modulate neuroelectrical activity and diminish subjective psychological distress during an acute laboratory stressor.
Limits
The abstract reports only p-values without absolute effect sizes, confidence intervals, or numerical data for cardiovascular and cortisol outcomes. The findings reflect acute responses to an artificial laboratory stressor in a relatively small sample (approximately 25 participants per arm) and do not establish long-term efficacy or clinical utility for chronic stress.
Cited by
- context There is no evidence that Rhodiola rosea improves baseline resting heart rate variability over time.