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Multiple dosing of ephedra-free dietary supplements: hemodynamic, electrocardiographic, and bacterial contamination

L Foster1, M C Allan, A Khan

  • 1Department of Dietetics and Nutrition, College of Health Professions University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.

Clinical Pharmacology and Therapeutics
|January 31, 2013
PubMed

Insights

Ephedra-free dietary supplements can significantly increase heart rate and blood pressure, posing risks for individuals with cardiovascular conditions. Some supplements also contained harmful bacterial contamination.

Area of Science:

  • Cardiovascular Pharmacology
  • Dietary Supplement Analysis
  • Human Physiology

Background:

  • Ephedra alkaloids were removed from many dietary supplements due to safety concerns.
  • Ephedra-free alternatives are widely used for weight loss and athletic performance.
  • The cardiovascular safety of ephedra-free supplements requires thorough investigation.

Purpose of the Study:

  • To evaluate the cardiovascular effects of popular ephedra-free dietary supplements.
  • To assess the impact on heart rate (HR), blood pressure (BP), and electrocardiographic (ECG) parameters.
  • To determine caffeine content and identify potential contaminants in these supplements.

Main Methods:

  • A randomized, crossover study involving 12 healthy men.
  • Administration of four ephedra-free supplements with a 21-day washout period.
  • Continuous Holter monitoring for ECG and HR; automated BP measurements.
  • Analysis of caffeine content, microbial load, and serum caffeine levels.

Main Results:

  • Significant increases in systolic and diastolic blood pressure (SBP/DBP) were observed.
  • All supplements led to increased heart rate and decreased bradycardia runs.
  • Frequent abnormal atrial/ventricular events and sympathomimetic symptoms were reported.
  • Two supplements showed heavy contamination with Bacillus species.

Conclusions:

  • Ephedra-free dietary supplements can adversely affect cardiovascular parameters.
  • The use of these supplements is not recommended for individuals with pre-existing cardiovascular conditions.
  • Contamination with microbial species poses an additional health risk.

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