Curcumin reduces malondialdehyde and improves antioxidants in humans with diseased conditions: a comprehensive meta-analysis of randomized controlled trials

This systematic review and meta-analysis was conducted to collate the effects of curcumin on MDA and antioxidant markers in individuals with diseased conditions. In this study the research question was "does curcumin supplementation improves oxidative stress and antioxidant defense enzymes in human subjects compared to a group without curcumin supplementation?

This research included randomized controlled trials published in English in any year, in which intervention with curcumin was compared to either placebo, or standard of care or no intervention. Pubmed, Embase, Cochrane Central, Scopus and Google Scholar were searched. Meta-analysis was performed using RevMan (version 5.3), with standardized mean differences (SMD) and random-effects models.

One hundred twenty-seven titles and abstracts were identified which 17 articles were included for final analysis. The number of participants ranged from 22 to 160 across the included studies. The duration of intervention, dose of curcumin and location of outcomes measurements varied across the studies. Curcumin significantly reduced MDA [SMD -0.46 (95% CI: -0.68 to -0.25)] and increased superoxide dismutase (SOD) [0.82 (0.27 to 1.38)], catalase [10.26 (0.92 to 19.61)], and glutathione peroxidase [8.90 (6.62 to 11.19)] when compared with control group. Subgroup analyses displayed that curcumin could significantly reduce MDA levels with or without use of piperine, however it could increase SOD level in presence of piperine.

These findings suggest that curcumin may be used as an adjunct therapy in individuals with oxidative stress. The administration of piperine with curcumin may enhance the efficacy of curcumin on antioxidant defense system.