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.