Tiran, D. (2012). Ginger to reduce nausea and vomiting during pregnancy: Evidence of effectiveness is not the same as proof of safety. Complimentary Therapies in Clinical Practice, 18(1), 22-25. doi: 10.1016/j.ctcp.2011.08.007
This article presents a systemic review of the mechanism and safety of using ginger to treat nausea and vomiting in pregnancy (NVP). In the article, the author first introduced the history of ginger as a traditional remedy in some eastern countries, then discussed the potential risk of several different forms of ginger that were available in the UK market. After that, the author explored the mechanisms of ginger’s anti-emetic function. Ginger can inhibit serotonin receptor and suppress vasopressin, as well as reduce tachygastric activity. However, the exact mechanism still remains unclear. The author pointed out that there was no consistency in dosages and forms of ginger among current studies, and the differences between nausea and vomiting was not fully understood. Next, the author discussed the safety of using ginger. The author believed that ginger should be treated as a pharmacological medication rather than a “natural” remedy. Therefore, it should be administered with safe dosages and be obtained from the correct plant, Zingiber officinale. Following that, the author discussed ginger’s potential adverse effects, drug-drug interactions, as well as contraindications and precautions. For example, ginger should be contraindicated for women who have a history of miscarriage because anticoagulation is one of its notable side effects. At the end of article, the author offered a contraindications and precautions checklist, which is very useful for health care providers to identify which women should avoid ginger. The limitation of this article is that it did not emphasize ginger’s therapeutic effects. The strength of this article is the valuable safety checklist. Overall, this article increased the awareness that ginger, although a natural remedy, has side effects and contraindications too.
Ozgoli, G., Goli, M. & Simbar, M. (2009). Effects of ginger capsules on pregnancy, nausea, and vomiting. The Journal of Alternative and Complementary Medicine, 15(3), 243-246. doi: 10.1089/acm.2008.0406
This article describes a single blind clinical trial to determine function of ginger on nausea and vomiting in pregnancy (NVP). 70 pregnant women who experienced nausea and vomiting before 20 weeks of gestation participated this study. Prior to the treatment with ginger, the baseline levels of nausea and vomiting symptoms were measured via a standard visual analogue scale. The participants were randomly assigned to the experimental group and control group. In the experimental group, 35 participants were treated with ginger at a dose of 1000mg/day for 4 days. 35 participants in the control group were treated with a placebo (lactose) with the same dose and prescription form. The treatment effects were measured by asking participants to finish the 4-page questionnaire and record nausea intensity twice a day (3 participants from experimental group failed to complete the questionnaire). A statistically significant decrease in the nausea and vomiting intensity with ginger treatment was reported. 85% of women who received the ginger treatment reported an improvement of nausea symptoms, while only 56% reported improvement in the control group. In addition, the vomiting times for the pregnancy are also significantly decreased in the experimental group comparing to control group (50% versus 9%). The materials and methods section was well developed with clear description of experimental design, samples selection, data collection and analysis. The strengths of this article are the rigorous experimental design and large sample size. The limitation of this study, as mentioned by the authors, is the short assessment period. As a result, some ginger adverse effects may not be able to discover. The findings of this study provide some evidence-based information about effects of ginger for NVP.