| Background & aims: Recent trial studies have found that conjugated linoleic acid (CLA) supplementation benefi-
cially reduces oxidative stress markers but, there is no definitive consensus on this context. The present system-
atic review and meta-analysis aimed to investigate the effect of CLA supplementation on oxidative stress para-
meters.
Methods: We searched PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar databases until
September 2021 to identify randomized controlled trials (RCTs) assessing CLA supplementation effects on ox-
idative markers including malondialdehyde (MDA), 8-isoprostanesF2α (8-iso-PGF2α), and glutathione peroxi-
dase (GPx). Summary estimates and corresponding 95% confidence intervals (CI) were derived via the DerSi-
monian and Laird method using a random-effects model.
Results: A total of 11 RCTs were included. The obtained results show that CLA supplementation caused a signifi-
cant decrease in MDA concentrations (Hedges's: −0.35; 95% CI: −0.70 to −0.01, P = 0.04, I2 = 62.1%, n = 7),
and also significantly increased 8-iso-PGF2α levels (Hedges's: 1.45; 95% CI: 0.98 to 1.91, P˂0.001, I2 = 42.9%,
n = 4). However, the results showed that supplementation with CLA did not significantly change the concentra-
tions of GPx (Hedges's: 0.30; 95% CI: −0.04 to 0.64, P = 0.08, I2 = 0.0%, n = 3).
Conclusion: It seems this supplement can be used as a dietary supplement to improve oxidative stress parameters.
However, further studies are required to demonstrate present results. |