Ginger (Zingiber officinale) and Nausea: evidence and sources

Introduction Nausea and vomiting (NV) affect up to 85% of pregnant women, which has multiple effects on pregnancy outcome. The truth etiology of nausea and vomiting in pregnancy (NVP) is still unknown. Considering the potential teratogenic effect in fetus due to chemical drugs, ginger can be used to treat nausea and vomiting during pregnancy. Reports have shown that ginger can reduce the severity of NV, however, these results are controversial. Therefore, this meta-analysis aims to explore the effect of ginger in the treatment of nausea and vomiting during pregnancy compared with placebo and vitamin B6. Methods The randomized control trials (RCTs) on the association with ginger and pregnancy-related nausea and vomiting were searched and identified in two databases Web of Science and PubMed (up to April 2019). Stata software was used to conduct meta-analysis. In addition, the source of heterogeneity explored by metaregression, sensitivity analysis, subgroup analyses, the publication bias were assessed by Egger's tests and Funnel plot, p Results Thirteen studies involving 1174 subjects were included in this meta-analysis. The result demonstrated that ginger intervention has significant effect in improving general symptom of NVP [OR = 7.475, 95% CI = (4.133, 13.520), I 2 = 30.1%], relieving severity of nausea [SMD = 0.821, 95% CI = (0.585, 1.056), I 2 = 38.9%], but not significant in reducing vomiting [SMD = 0.549, 95% CI = (-0.268, 1.365), I 2 = 91.4%], compared with placebo. Besides, ginger intervention has no significant effect on improving general symptom of NVP [OR = 1.239, 95% CI = (0.495, 3.102), I 2 = 57.3%], relieving severity of nausea [SMD = 0.199, 95% CI = (-0.102, 0.500), I 2 = 65.7%], reducing vomiting [SMD = 0.331, 95% CI = (-0.145, 0.808), I 2 = 85.9%], compared with vitamin B6. Conclusions Ginger supplementation significantly relieve general NVP symptom and nausea compared with placebo, but no significant effect on vomiting. Moreover, ginger is more effective than vitamin B6 in treating NVP, although, there were no significant differences. Further, rigidly designed RCTs with larger sample sizes are needed to verify the effectiveness of ginger supplementation for treatment NVP compared with vitamin B6.

Background and objectives Nausea and vomiting during pregnancy (NVP) occur commonly. Possible harmful side-effects of conventional medicine to the fetus create the need for alternative options to relieve NVP. This systematic review (SR) investigated current evidence regarding orally administered ginger for the treatment of NVP. The primary objective was to assess the effectiveness of ginger in treating NVP. The secondary objective was to assess the safety of ginger during pregnancy. Methods A comprehensive electronic bibliographic database search was carried out. Randomized controlled trials (RCTs) of the efficacy of orally administered ginger, as treatment for NVP in pregnant women at any stage of pregnancy, published in English, were included. Two researchers independently extracted data and assessed trial quality. RevMan5 software (Cochrane Collaboration) was used for data analysis. p Results Twelve RCTs involving 1278 pregnant women were included. Ginger significantly improved the symptoms of nausea when compared to placebo (MD 1.20, 95% CI 0.56-1.84, p = 0.0002, I² = 0%). Ginger did not significantly reduce the number of vomiting episodes during NVP, when compared to placebo, although there was a trend towards improvement (MD 0.72, 95% CI -0.03-1.46, p = 0.06, I² = 71%). Subgroup analyses seemed to favor the lower daily dosage of Conclusions This review suggests potential benefits of ginger in reducing nausea symptoms in pregnancy (bearing in mind the limited number of studies, variable outcome reporting and low quality of evidence). Ginger did not significantly affect vomiting episodes, nor pose a risk for side-effects or adverse events during pregnancy. Based on evidence from this SR, ginger could be considered a harmless and possibly effective alternative option for women suffering from NVP. International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42011001237.