Ginger (Zingiber officinale) is a traditional food-based preparation which has been used in multiple studies to treat nausea and vomiting from a wide range of causes. It has shown to be beneficial at treating morning sickness, post-operative nausea and vomiting, and many studies have found that it prevents or reduces the severity of chemotherapy-induced nausea and vomiting. However, the findings from studies on ginger for chemotherapy induced nausea and vomiting (CINV) are mixed, with some studies revealing that its effects are minimal or even detrimental.
Ginger is administered both as an essential oil via inhalation and as a dietary supplement via ingestion of doses of 1 gram per day. These doses are most often administered in capsules of 250mg once every 6 hours or twice every 12 hours. Most studies begin ginger supplementation on the first day of chemotherapy and continue for 3-6 days each cycle.
“Ginger for Chemotherapy Induced Nausea and Vomiting: A Meta-Analysis of Randomized, Controlled Clinical Trials“
The analysis was restricted to studies which used any form of plain ginger for chemotherapy induced nausea and vomiting. Studies on ginger in combination with other anti-emetic drugs were included, but studies on blends containing ginger with other herbs or dietary supplements were excluded. Additionally, the outcome of interest must be the severity of acute nausea and/or vomiting. Studies which only evaluated delayed nausea and vomiting were excluded, and studies which evaluated the incidence of nausea or vomiting were excluded. Acute nausea and vomiting was defined as the first 24 hours after the chemotherapy session.
The purpose of this meta-analysis is to evaluate the data on ginger as a treatment to reduce the severity and duration of nausea and vomiting within the first 24 hours of chemotherapy, and to evaluate the potential for moderator variables that may influence those effects. Moderators in this analysis include ginger preparation type, cancer diagnosis, and chemotherapeutic agent.
Studies for this analysis were identified from the scientific literature and from unpublished works during several months in mid-2018. Unbiased standard mean difference was calculated for each study using Comprehensive Meta Analysis version 3. Of the 10 studies included in this analysis, 8 provided information on severity of acute nausea as an outcome, 7 provided information on severity of acute vomiting as an outcome, and 1 provided information on severity of acute nausea and vomiting combined as an outcome. Nausea and vomiting effect sizes were analyzed as individual outcomes and then combined for total analysis.
Findings: Ginger for Chemotherapy Induced Nausea and Vomiting
A total of 775 participants in this analysis received ginger for chemotherapy induced nausea and vomiting and 502 participants were in control groups, reflecting a total of 1,277 participants across 10 studies. Mean age of the 1,277 participants ranged from 15 to 57 and over half of the studies were conducted exclusively on females. The other four studies included between 7% and 72% male patients. The cancer diagnoses ranged, with most of the female specific studies including a diagnosis of breast cancer in the inclusion criteria. Cisplatin was the most commonly used chemotherapeutic agent. Other studies included patients with a range of cancer diagnoses, treatment progress, and chemotherapeutic agents.
Overall, 16 effect sizes were calculated from the studies. Six studies provided enough data to calculate effect sizes for vomiting and nausea individually. For these studies, the effect sizes were combined for total analysis to reflect the total effect of ginger on CINV. The quantitative synthesis of the effects yielded an unbiased standardized mean difference of -0.155 (SE=0.083; 95% CI: -0.318:0.007, p = 0.061), using a random effects model. Using ginger to treat chemotherapy-induced nausea and vomiting may be effective at reducing severity.
Ginger Herb vs Ginger Essential Oil
This analysis included 1 study which evaluated ginger essential oil, 6 studies which evaluated a crude ginger powdered extract, and 3 studies which identified standardization of the ginger product. The criterion for this analysis was the type of ginger administered to treat CINV.
The moderator analysis revealed that ginger is most effective at treating CINV when the supplement is an herbal product rather than an essential oil. Standardized ginger has an effect on CINV severity with an effect size of -0.170 (SE=0.114; 95% CI: -.393:0.054, p = .137). This differs from the effect size of -0.187 (SE=0.143; 95% CI: -0.467:0.093, p = .190) found from the powdered herb and the effect size of -0.078 (SE=.258; 95% CI: —0.584:0.429, p = .763) found in the one study testing ginger essential oil.
While many chemotherapeutic drugs are known to cause CINV, cisplatin has particularly high emetogenic potential. This analysis included 3 studies which evaluated the effects of ginger on cisplatin-induced nausea and vomiting. The other 7 studies included participants with a combination of agents with less emetogenic potential. The criterion for this analysis was the type of chemotherapeutic agent.
The moderator analysis revealed that ginger is less effective at treating CINV due to cisplatin than for other chemotherapeutic agents. Ginger has an effect size of -0.025 (SE=0.098; 95% CI: -.168:0.217, p = .800) for cisplatin-induced nausea and vomiting, while it has an effect size of -0.268 (SE=0.115; 95% CI: -.494: -0.043, p = .020) for other chemotherapeutic agents. This indicates that ginger is not effective at treating CINV due to cisplatin, but produces a statistically significant effect on nausea and vomiting caused by other chemotherapeutic agents.
This analysis included 5 studies which evaluated ginger for CINV as a result of breast cancer treatment. The other 5 studies included participants with different types of cancer. The criterion for this analysis was patient diagnosis.
Ginger is more effective at treating CINV from chemotherapy for breast cancer (ES: -0.222; SE=0.126; 95% CI: -.468 – 0.024, p = .077) than chemotherapy for other cancer diagnoses (ES:-0.112; SE=0.119; 95% CI: -.345:0.122, p = .348), using a random effects model. Ginger supplementation has a larger effect on breast cancer related CINV than chemotherapy for other cancer diagnoses.
Supplementation with ginger (Zingiber officinale) has a small but beneficial effect on the severity of acute nausea and vomiting. The supplement is particularly beneficial for breast cancer, as opposed to other diagnoses, and it is most significant when used for acute CINV caused by chemotherapeutic agents other than cisplatin. Based on the existing body of knowledge, the herbal supplement is more effective than aromatherapy treatment with the essential oil.
Ginger should be standardized with rigorous quality control to ensure that the product contains the active ingredients. However, standardization does not appear to significantly influence total efficacy. Ginger is widely available and can be used on an as-needed basis starting the first day of chemotherapy treatment. Because the herbal supplement is well tolerated and does not pose a risk of interaction, ginger for chemotherapy induced nausea and vomiting improves overall quality of life among patients undergoing chemotherapy as it reduces overall severity of CINV.
For More Information
The study is being published early 2019. Because all research conducted by the Franklin Institute of Wellness research department is self funded, open access was not purchased for this publication. To learn more about the study, a video lecture series given by Dr. Hawkins, the lead researcher, will be available in our College Bookstore.
Disclosures: This study was funded by the Franklin Institute of Wellness and was conducted through a collaboration with the Cancer Specialists of North Florida. The researchers who conducted this study are fully trained and certified in human participant research and do not have any conflicts of interest to declare.