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Bjaoxfordjournals.lovelossweight.comBritish Journal of Anaesthesia 84 (3): 367–71 (2000)
Efficacy of ginger for nausea and vomiting: a systematic review of
randomized clinical trials
E. Ernst* and M. H. Pittler
Department of Complementary Medicine, School of Postgraduate Medicine and Health Sciences, University of Exeter, 25 Victoria Park Road, Exeter EX2 4NT, UK Ginger (Zingiber officinale) is often advocated as beneficial for nausea and vomiting. Whetherthe herb is truly efficacious for this condition is, however, still a matter of debate. We haveperformed a systematic review of the evidence from randomized controlled trials for or againstthe efficacy of ginger for nausea and vomiting. Six studies met all inclusion criteria and werereviewed. Three on postoperative nausea and vomiting were identified and two of thesesuggested that ginger was superior to placebo and equally effective as metoclopramide. Thepooled absolute risk reduction for the incidence of postoperative nausea, however, indicateda non-significant difference between the ginger and placebo groups for ginger 1 g taken beforeoperation (absolute risk reduction 0.052 (95% confidence interval –0.082 to 0.186)). One studywas found for each of the following conditions: seasickness, morning sickness and chemotherapy-induced nausea. These studies collectively favoured ginger over placebo.
Br J Anaesth 2000; 84: 367–71
Keywords: pharmacology, ginger; vomiting, nausea; vomiting, incidence; research, emesis;
Accepted for publication: September 1, 1999 Ginger (Zingiber officinale) has been used for medicinal purposes since antiquity. In particular, it has been an Systematic literature searches were performed to identify important plant for the traditional Chinese and Indian all RCTs on ginger for nausea and vomiting. Computerized pharmacopoeia. One of its indications has always been the treatment of nausea and vomiting. The aromatic, spasmolytic CISCOM (Research Council for Complementary Medicine, carminative and absorbent properties of ginger suggest that London) and the Cochrane Library (all from their respective it has direct effects on the gastrointestinal tract.1 German inception to November 1997). The search terms used were and European monographs on ginger are available2 3 and ginger, Zingiber officinale and Ingwer (German term for both list nausea/vomiting as indications. Recently, the US Zingiber officinale). A manual search was performed using pharmacopoeia has approved ginger and powdered ginger the bibliographies of studies and reviews located through monographs for inclusion in the National Formulary.4 the computer search and through scanning our own files.
The notion that ginger may be effective for nausea and In addition, manufacturers of ginger preparations were vomiting is supported by several lines of evidence. Animal asked to contribute published and unpublished material. No experiments suggest that ginger has antiemetic activity5 when nausea is induced by cisplatin6 or cyclophosphamide.7 Only double-blind, placebo-controlled RCTs of ginger Studies in healthy human volunteers suggest that ginger monopreparations for nausea and vomiting were included.
reduces experimentally induced nausea.8 9 Furthermore, Studies on experimentally induced nausea or vomiting, or non-randomized, non-placebo-controlled studies suggest an both, were excluded. All studies were assessed independ- antiemetic effect in human patients.10 11 However, these ently by both authors. Data were extracted in a standardized, data are insufficient to evaluate whether or not ginger is predefined manner. The methodological quality of each truly efficacious for clinical nausea and vomiting.
study was assessed using the scoring system developed by In this study, we have assessed the available evidence Jadad and colleagues.12 The authors met to agree consensus from randomized, controlled trials (RCT) for or against the on the assessed data. Disagreements were settled by dis- efficacy of ginger for clinical nausea and vomiting.
The Board of Management and Trustees of the British Journal of Anaesthesia 2000 Statistical combination of data was performed for studies women before laparoscopic surgery to one of three similar on postoperative nausea. The incidence of postoperative treatment groups. The medication was given 1 h before nausea was defined as the common end-point and used to surgery and the incidence of nausea and vomiting was 21%, assess differences between treatment and control interven- 27% and 41% in the ginger, metoclopramide and placebo tion. The absolute risk reduction and 95% confidence groups, respectively. Significantly (Pϭ0.006) fewer patients intervals were calculated using standard meta-analysis with nausea were reported in the ginger group compared software (RevMan 3.01, Cochrane Collaboration). The num- ber-needed-to-treat was calculated as the inverse of the In a study by Arfeen and colleagues,20 108 women were allocated randomly to receive ginger 0.5 g, ginger 1 g orplacebo before laparoscopic surgery. The incidence ofnausea and vomiting was monitored 3 h after operation.
There were no significant differences between groups.
Six studies met all of our criteria and were reviewed.15–20 Data from RCT on postoperative nausea18–20 were suitable The assessment of methodological quality revealed a score for statistical pooling. The pooled absolute risk reduction of at least 3 of 5 points in the majority of studies.
for the incidence of postoperative nausea indicated a non- The studies related to four different clinical conditions: significant difference between the ginger group treated with ginger 1 g before operation and the placebo group (absolute nausea and postoperative nausea. Most were conducted on risk reduction 0.052 (95% confidence interval –0.082 to postoperative nausea.18–20 Key data are summarized in 0.186)). These values indicate a point estimate of the number-needed-to-treat of 19 and a 95% confidence interval Grøntved and colleagues15 studied 80 Danish cadets, which also includes the possibility of no benefit.21 allocated randomly to receive either one dose of gingerpowder 1 g or placebo. Symptoms of seasickness were Discussion
evaluated during the subsequent 4 h. Volunteers who The majority of the studies reported that ginger powder 1 g received ginger powder suffered less seasickness compared daily alleviated clinical nausea of diverse causes. One study with those who received placebo. The difference between on postoperative nausea,20 however, showed no significant ginger powder and placebo was statistically significant beneficial effects of ginger compared with placebo and, (PϽ0.05) 4 h after receiving the medication.
indeed, between doses of 0.5 g and 1 g of ginger powder.
Fischer-Rasmussen and colleagues16 conducted a small This study is also the most rigorous on this indication. The crossover study in 27 women suffering from hyperemesis discrepancy between this negative outcome and the positive gravidarum. Patients received ginger powder 250 mg or results from other RCT is not readily explicable.
placebo, four times daily for 4 days. Sickness was assessed There are only few data on the actions of ginger.
using a symptom score. The results suggested a significantly Gingerols, in particular 6-gingerol, have been identified as (PϽ0.05) greater symptomatic benefit after administration the active ingredient of ginger, and are also responsible for its characteristic taste. There are several mechanisms which One RCT was identified for chemotherapy-induced could explain the possible antiemetic effects of ginger. In nausea.17 Forty-one patients suffering from leukaemia were an animal model, for instance, it was demonstrated that allocated randomly to one of two groups to receive either 6-gingerol enhanced gastrointestinal transport.22 This and oral ginger or placebo, after administration of compazine other compounds of ginger have also been shown to i.v. The results suggested a significant (P value not reported) have anti-hydroxytryptamine activity in isolated guineapig reduction in nausea in patients who received ginger com- ileum.23 24 Galanolactone, another constituent of ginger, is pared with those who received placebo. This study has only a competitive antagonist at ileal 5-HT3 receptors.24 Thus been published as an abstract and crucial details were antiemesis could be brought about by effects on the gastric system through 5-HT3 antagonism. This hypothesis is Bone and colleagues18 studied 60 women before major weakened by the results of a randomized, placebo-con- gynaecological operations. Patients were allocated randomly trolled, crossover study in human volunteers reporting that to receive ginger 1 g, metoclopramide 10 mg or placebo as oral ingestion of powdered ginger root did not affect gastric a single dose given with preoperative medication. The emptying rate.25 In contrast, effects on the central nervous severity of postoperative nausea was assessed on a four- system may be involved. This notion is strengthened by the point scale. The incidence of nausea during the first 24 h finding that, in an animal model, oral 6-gingerol prevented after surgery was 28%, 30% and 51% in the ginger, vomiting in response to cyclophosphamide.7 A central effect metoclopramide and placebo groups, respectively. A statist- is also implicated by studies reporting that ginger partly ically significant (PϽ0.05) difference in favour of ginger prevents motion sickness symptoms in healthy human compared with placebo was reported for the total number volunteers.8–9 Another study investigating motion sickness, however, reported no effects of ginger on the vestibular Phillips, Hutchinson and Ruggier19 randomized 120 Efficacy of ginger for nausea and vomiting Duration
With a herb commonly used as a foodstuff and spice, one is inclined to assume that it is free of serious adverse psychophysics. Lancet 1982; i: 655–6
effects. However, this can be a dangerous fallacy.27 For 9 Grøntved A, Hentzer E. Vertigo-reducing effect of ginger root.
A controlled clinical study. J Otorhinolaryngol Relat Spec 1986; instance, in doses taken with food, a spice may be safe, yet 48: 282–6
when taken in higher doses as a drug, this might not apply.
10 Meyer K, Schwartz J, Crater D, Keyes B. Zingiber officinale
There were no reports of adverse reactions to ginger (ginger) used to prevent 8-mop associated nausea. Dermatol compared with placebo in any of the above studies. The Nurs 1995; 7: 242–4
British Herbal Compendium documents no adverse effects 11 Schmid R, Schick T, Steffen R, Tschopp A, Wilk T. Comparison
of ginger.28 The German monograph2 warns that ginger of seven commonly used agents for prophylaxis of seasickness.
should not be taken during pregnancy. The caution is based J Travel Med 1994; 1: 203–6
12 Jadad AR, Moore RA, Carrol D, et al. Assessing the quality of
on data suggesting that ginger is mutagenic in several reports of randomized clinical trials: is blinding necessary? test systems.29–31 However, the situation is complex and Control Clin Trials 1996; 17: 1–12
antimutagenic effects have also been reported.32 Systematic 13 Cook RJ, Sackett DL. The number needed to treat: a clinically
studies of ginger or its constituents in mammalian cell useful measure of treatment effect. BMJ 1995; 310: 452–4
cultures have not been reported. There is also no evidence 14 Moore A, McQuay H. Calculating NNTs. Bandolier 1997; 36: 2
that ginger is harmful when taken by pregnant women.16 15 Grøntved A, Brask T, Kambskard J, Hentzer E. Ginger root
However, in the light of suspicion of mutagenicity it seems against seasickness: A controlled trial on the open sea. Acta
Otolaryngol 1988; 105: 45–9
16 Fischer-Rasmussen W, Kjær SK, Dahl C, Asping U. Ginger
Publication bias is of concern for all systematic reviews treatment of hyperemesis gravidarum. Eur J Obstet Gynecol which may lead to a false positive overall result. It is known Reprod Biol 1990; 38: 19–24
that negative studies tend to remain unpublished.33 The 17 Pace JC. Oral ingestion of encapsulated ginger and reported
literature relating to complementary medicine could be self-care actions for the relief of chemotherapy-associated particularly distorted.34 The data available are by no means nausea and vomiting. Dissertations Abstracts Int 1987; 47: 3297-B
beyond criticism. The outcome measures used in the above 18 Bone ME, Wilkinson DJ, Young JR, McNeil J, Charlton S.
Ginger root–a new antiemetic: The effect of ginger root on trials may be of debatable reliability, sample sizes are postoperative nausea and vomiting after major gynaecological usually small and power calculations are mostly lacking.
surgery. Anaesthesia 1990; 45: 669–71
Modern antiemetic agents include droperidol, the prokin- 19 Phillips S, Ruggier R, Hutchinson SE. Zingiber officinale (Ginger)–
etic metoclopramide and the 5-HT3 receptor antagonist an antiemetic for day case surgery. Anaesthesia 1993; 48: 715–17
odansetron.35 The latter is superior to placebo and comparat- 20 Arfeen Z, Owen H, Plummer JL, Ilsley AH, Sorby-Adams RAC,
ive studies demonstrated no significant differences com- Doecke LJ. A double-blind randomized controlled trial of ginger pared with droperidol or metoclopamide.36 In comparative for the prevention of postoperative nausea and vomiting.
Anaesth Intensive Care 1995; 23: 449–52
studies of ginger and metoclopramide,18 19 no significant 21 McQuay HJ, Moore RA. Using numerical results from systematic
difference was found between treatments.
reviews in clinical practice. Ann Intern Med 1997; 126: 712–20
In summary, we found that ginger is a promising antiem- 22 Yamahara J, Huang QR, Li Y, Xu L, Fujimura H. Gastrointestinal
etic herbal remedy, but the clinical data to date are insuffi- motility enhancing effect of ginger and its active constituents.
cient to draw firm conclusions. Further rigorous studies are Chem Pharm Bull (Tokyo) 1990; 38: 430–1
needed to establish whether ginger is efficacious for clinical 23 Yamahara J, Huang QR, Iwamoto M, Kobayashi G, Matsuda H,
Fujimura H. Active components of ginger exhibiting anti-
serotinergic action. Phyto Res 1989; 3: 70–1
24 Huang Q, Iwamoto M, Aoki S, et al. Anti-5-hydroxytryptamine
effect of galanolactone, diterpenoid isolated from ginger. Chem 1 Tyler VE. Some recent advances in herbal medicine. Pharm Int
Pharm Bull (Tokyo) 1991; 39: 397–9
1986; 7: 203–7
25 Phillips S, Hutchinson S, Ruggier R. Zingiber officinale does not
2 Kommission E. Monographie Zingiberis rhizoma. Bundesanzeiger,
affect gastric emptying rate. A randomised, placebo-controlled, crossover trial. Anaesthesia 1993; 48: 393–5
3 ESCOP Monograph. Zingiberis rhizoma (Ginger). Europ. Scientific
26 Holtmann S, Clarke AH, Scherer H, Hohn M. The anti-motion
sickness mechanism of ginger. A comparative study with placebo 4 USP adopts ginger monograph. Herbalgram 1997; 41: 12
and dimenhydrinate. Acta Otolaryngol (Stockh) 1989; 108: 168–74
5 Frisch C, Haseno¨hrl RU, Mattern CM, Ha¨cker R, Huston JP.
27 Ernst E, De Smet PAGM, Shaw D, Murray V. Traditional
Blockage of lithium chloride-induced conditioned place aversion remedies and the test of time. Eur J Clin Pharmacol 1998; 54:
as a test for antiemetic agents: comparison of metoclopramide with combined extracts of Zingiber officinale and Ginkgo biloba.
28 Bradley P, ed. British Herbal Compendium. Bournemouth: British
Pharmacol Biochem Behav 1995; 52: 321–7
6 Sharma SS, Kochupillai V, Gupta SK, Seth SD, Gupta YK.
29 Abraham S, Abraham SK, Radhamony G. Mutagenic potential
Antiemetic efficacy of ginger (Zingiber officinale) against cisplatin- of the condiments, ginger and turmeric. Cytologia 1976; 41:
induced emesis in dogs. J Ethnopharmacol 1997; 57: 93–6
7 Yamahara J, Rong HQ, Naitoh Y, Kitani T, Fujimura H. Inhibition
30 Nagabhushan M, Amonkar AJ, Bhide SV. Mutagenicity of gingerol
of cytotoxic drug-induced vomiting in suncus by a ginger and shogaol and antimutagenicity of zingerone in salmonella/ constituent. J Ethnopharmacol 1989; 27: 353–5
microsome assay. Cancer Lett 1987; 36: 221–33
Efficacy of ginger for nausea and vomiting 31 Soudamini KK, Unnikrishnan MC, Sukumaran K, Kuttan R.
34 Ernst E, Pittler MH. Alternative therapy bias. Nature 1997;
Mutagenicity and anti-mutagenicity of selected spices. Indian J Physiol Pharmacol 1995; 39: 347–53
35 Baines MJ. Nausea, vomiting and intestinal obstruction. BMJ
32 Corrigan D. Zingiber officinale. In: De Smet PAGM, Keller K,
1997; 315: 1148–50
Ha¨nsel R, Chandler RF, eds. Adverse Effects of Herbal Drugs, 36 Trame`r MR, Moore RA, Reynolds DJM, McQuay HJ. A
vol. 3. Berlin: Springer Berling, 1997; 215–28 quantitative systematic review of odansetron in treatment of 33 Easterbrook PJ, Berlin JA, Gopalan R, Matthews DR. Publication
established postoperative nausea and vomiting. BMJ 1997; 314:
bias in clinical research. Lancet 1991; 337: 867–72
Zoo Biology 19:393–403 (2000) Tuberculosis in Elephants in North America Susan K. Mikota,1 R. Scott Larsen,2 and Richard J. Montali3* 1Audubon Center for Research of Endangered Species, New Orleans, Louisiana2Department of Clinical Sciences, College of Veterinary Medicine and BiomedicalSciences, Colorado State University, Fort Collins, Colorado3Department of Pathology, Smithsonian Nat