Effects of antioxidants on oxidative stress in adult patients with coronary artery disease: A systematic review

Abstract

Background: Oxidative stress (OS) accelerates the pathogenesis of coronary artery disease (CAD) by contributing to atherosclerotic plaque formation. Current research indicates that antioxidants can mitigate OS by reducing the production of free radicals. Despite many studies that have tested the effects of antioxidants on oxidative stress in patients with CAD, the literature still lacks an updated and comprehensive systematic review. The aim of this study was to identify the effects of administering exogenous antioxidants on OS levels among adult patients with CAD.

Methods: A systematic review searched PubMed, Medline, and CINAHL for randomized controlled trials (RCTs) published between January 2013 and May 2025, which examined antioxidants to lower OS in adult participants with CAD. Studies were excluded if participants had chronic or acute inflammatory conditions, renal failure, liver failure, or had undergone major operations before being enrolled.

Results: Among 2338 studies reviewed, 15 RCTs met the inclusion criteria. Out of the 15 RCTs, nine reported on supplemental antioxidants (i.e., L-carnitine and melatonin), and two reported on dietary antioxidants (Khorasan wheat diet and wine) that were effective at lowering OS (P < 0.05). One study found Brazil nuts (dietary antioxidants) ineffective at lowering OS. The three remaining RTCs reported that intravenously administered antioxidants, including alpha-lipoic acid, vitamin C, or N-acetylcysteine, significantly lowered OS.

Conclusions: The reviewed RTCs provide evidence that antioxidants may lower OS in patients with CAD. The utility of this conclusion is limited by the studies' methodologies that examine various antioxidants and measure OS through a variety of biomarkers. This heterogeneity in methodologies between studies indicates that further research is needed with standardized interventions and outcomes.

Keywords: Antioxidants; Coronary artery disease; Free radicals; Myocardial infarction; Oxidative stress.