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Why do antioxidants fail to provide clinical benefit?

Ascan Warnholtz1, Thomas Münzel

  • 1University Hospital Eppendorf, Division of Cardiology, Hamburg, Germany. muenzel@uke.uni-hamburg.de

Current Controlled Trials in Cardiovascular Medicine
|November 21, 2001
PubMed

Insights

Antioxidant supplements like vitamin E failed to improve outcomes for patients with coronary artery disease. Angiotensin-converting-enzyme (ACE) inhibitors, however, reduced cardiac events, suggesting enzymatic inhibition is a more effective treatment strategy.

Area of Science:

  • Cardiology
  • Pharmacology
  • Biochemistry

Background:

  • Randomized trials investigating antioxidant efficacy in coronary artery disease (CAD) have yielded disappointing results.
  • Vitamin E supplementation did not demonstrate any improvement in prognosis for CAD patients.
  • Angiotensin-converting-enzyme (ACE) inhibitors have shown promise in reducing adverse coronary events.

Purpose of the Study:

  • To evaluate the effectiveness of antioxidants versus ACE inhibitors in managing coronary artery disease.
  • To explore the underlying mechanisms of ACE inhibition in cardiovascular protection.

Main Methods:

  • Review of recent randomized trials on antioxidant and ACE inhibitor therapies in CAD patients.
  • Analysis of the impact of vitamin E on coronary-event rates.
  • Assessment of the effects of ACE inhibitors on prognosis and coronary-event rates.

Main Results:

  • Vitamin E supplementation showed no benefit in improving prognosis for patients with coronary artery disease.
  • Treatment with ACE inhibitors led to a reduction in coronary-event rates and improved patient prognosis.
  • ACE inhibition was linked to the prevention of angiotensin II formation, a key factor in superoxide production.

Conclusions:

  • Enzymatic inhibition of superoxide production, as achieved by ACE inhibitors, appears more beneficial than symptomatic superoxide scavenging for treating coronary artery disease.
  • Targeting the enzymatic pathways involved in atherosclerosis, rather than relying on antioxidants, may represent a superior therapeutic approach.

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