Key result
Ingestion of 1 or 2 g of ephedra dry extract dose-dependently increased sympathetic activity and impaired parasympathetic activity compared to placebo in healthy young adults.
Why the study?
Does ephedra alter autonomic nervous modulation measured by heart rate variability in healthy young adults?
RCT (n=20)
Double-blind
Crossover
Does ephedra alter autonomic nervous modulation measured by heart rate variability in healthy young adults?
Acute ingestion of ephedra dose-dependently increases sympathetic activity and impairs parasympathetic activity in healthy young adults.
Ephedra warrants clinical caution for autonomic imbalance; confirms dose-dependent sympathetic activation with parasympathetic impairment by HRV.
The aim of this study was to assess the acute effects of ephedra on autonomic nervous modulation by means of heart rate variability (HRV) analysis, using a randomized, double-blind, placebo-controlled, crossover design. On three separate days, 20 healthy subjects took capsules containing either 1 or 2 g of ephedra dry extract or a placebo, and the sequential percentage changes in HRV measures were compared. After the subjects took ephedra, the normalized low-frequency component (LF) and the ratio of LF to high-frequency component (HF) increased significantly in a dose-dependent manner, whereas the normalized HF (HF%) decreased significantly. We conclude that ingestion of ephedra tilts the sympathovagal balance dose-dependently toward increased sympathetic activity and impairs parasympathetic activity.
No takes yet. Share an insight, caveat, or question.
Yang et al. (2010) conducted an RCT in Healthy (n=20). Ephedra dry extract vs. Placebo was evaluated on Sequential percentage changes in heart rate variability (HRV) measures. Ingestion of 1 or 2 g of ephedra dry extract dose-dependently increased sympathetic activity and impaired parasympathetic activity compared to placebo in healthy young adults.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: