the influence of ginger (zingiber officinale) on human sperm quality and dna fragmentation: a double-blind randomized clinical trial

background: although the effectiveness of ginger as an antioxidant agent has been exploited, little human research has been conducted on its activity on male reproductive functions. objective: this study was designed to investigate the effects of ginger (zingiber officinale) on sperm dna fragmentation (sdf) in infertile men. materials and methods: this randomized double-blind, placebo-controlled trial with a 1:1 allocation was performed on 100 infertility treatment candidates who were admitted to royan institute for reproductive biomedicine, tehran, iran. patients were randomly assigned to receive one of two treatments: ginger and placebo. patients were given a 3-month oral treatment (members received capsules containing 250 mg of ginger powder twice a day in ginger and a placebo in other group). before and after treatment, standardized semen samples were obtained to determine sperm concentration, motility, and sdf according to world health organization. results: there was no significant difference between two groups regarding sdf at baseline (53.48. 95%ci: 37.95-69.02) in cases and (56.75, 95%ci: 40.01-73.5) in controls. the average positive percentage of sdf in patients receiving ginger (17.77, 95%ci: 6.16-29.39) was lower compared with placebo (40.54, 95%ci: 23.94-57.13) after three month of treatment (p=0.02). in multivariate analysis, sdf was significantly lower in patients receiving ginger compared with placebo (mean difference: 3.21, 95%ci: 0.78-5.63, p=0.009). there were no significant differences between two groups regarding to semen parameters. conclusion: the present study has demonstrated that ginger in a controlled study of efficacy was effective in decreasing sdf in infertile men.