Efficacy of ginger (zingiber officinale) in ameliorating chemotherapy-induced nausea and vomiting and chemotherapy-related outcomes: A systematic literature review update and meta-analysis

Nausea affects upwards of 60% of chemotherapy patients. Ginger has long been used in traditional medicine for alleviating nausea and vomiting; however, its use as an adjuvant therapy in patients undergoing chemotherapy is under-researched. Therefore, a systematic literature review and meta-analysis was undertaken to evaluate the efficacy of ginger supplementation in the prevention and management of chemotherapy-induced nausea and vomiting. Five electronic data bases were searched from database inception to October 2017. Intervention studies which administered ginger supplementation and a control (placebo or anti-emetic) to adults receiving chemotherapy were included,critically appraised using the Cochrane Risk of Bias tool, and pooled using meta-analysis. Seventeen papers were included. Ginger supplementation of any dose or duration had no effect on overall nausea incidence (OR: 0.80 [95% CI: 0.50–1.30] P = 0.37). There were trends towards improved nausea incidence for ginger supplementation of > 3-days (OR: 0.54 [95% CI: 0.23–1.23] P = 0.14; n = 5 studies; I2= 67%)and of doses > 1 g/day (OR: 0.56 [95% CI: 0.21–1.51] P = 0.25; n =4 studies; I2=67%). Ginger supplementation appeared to be more effective for acute nausea (OR:0.73 [95% CI: 0.50–1.06] P = 0.10; n =4 studies; I2= 57%) than delayed nausea (OR:1.03 [95% I:0.76–1.39]P = 0.87; I2= 20%). Ginger administration for > 3-days significantly reduced overall vomiting incidence (OR: 0.58 [95% CI: 0.38–0.90] P =0.01; n = 5 studies; I2= 74%) and delayed vomiting incidence (OR:0.44 [95% CI: 0.25–0.78] P = 0.005; n = 3 studies; n = 239 participants; I2= 83%). Sensitivity analysis did not explain the substantial heterogeneity in the pooled outcomes. Ginger supplementation of >1 g/day for > 3-days may improve chemotherapy-induced nausea and vomiting incidence; however, existing research remains inconsistent.Further research using strong designs, adequate sample sizes and standardized ginger products is warranted prior to routine clinical prescription.