Motion sickness:

In a small cross-over design, double-blind, randomised placebo-controlled study, 18 healthy volunteers with a history of motion sickness were included. Motion sickness was induced by movement and 13 out of the 18 participants developed nausea. The effect of ginger (1000 and 2000 mg ginger capsules or placebo with water 1 hour before circular vection) on nausea and gastric motion was evaluated. Pre-treatment with 1000 mg ginger capsules effectively reduced the nausea, gastric activity and plasma vasopressin release caused by circular vection (Lien et al. 2003) but further studies are needed, as this is the only clinical trial reported for motion sickness.

Pregnancy-induced nausea and vomiting (PNV):

A systematic review of the effectiveness of ginger, which included four randomised clinical trials, found its use to be safe and effective in the treatment of PNV compared to placebo and vitamin B₆. Nevertheless, the authors highlighted that the use of ginger in this population is not without risk (Ding et al. 2013). A previous assessment on its use during pregnancy advised women experiencing nausea and vomiting in pregnancy to be cautious (Tiran 2012). A Cochrane review found that ginger may be helpful to women with PNV, but the evidence was limited and inconsistent (Matthews et al. 2010). No beneficial effects were observed when ginger oil was used as aromatherapy for pain management during childbirth (Smith et al. 2011).

Chemotherapy-induced nausea and vomiting (CINV):

A systematic literature review found mixed results with two out of seven studies showing no benefits, three with some benefit on acute nausea and/or delayed nausea (when combined with standard anti-CINV treatment), and two reported an equal effect to metoclopramide (Marx et al. 2013). The lack of consistency in the trials’ methodology makes it difficult to draw any clinical recommendation for its use in CINV as yet.

Prevention and treatment of postoperative nausea and vomiting (PONV):

A meta-analysis which included 363 patients on a fixed dose of ginger showed that a dose of at least 1 g of ginger was more effective than placebo on 24-hour PONV (Chaiyakunapruk et al. 2006). A previous systematic review found no clinical relevance for its use in PONV (Morin et al. 2004) but this review included various dose regimens which were not comparable.

Irritable bowel syndrome (IBS):