Ginger is a commonly used culinary and medicinal herb that is benign and may be helpful for nausea and vomiting.
[LFODPKM ] Letter Key
Latin Name
Zingiber officinale Roscoe
Family
Zingiberaceae
Other Common Names
Common ginger, zingiber
Description
- Ginger is a tropical plant used as a spice, as well as medicinally.
- It is a common ingredient in almost half of Chinese and Japanese herbal medicines.
Part Used
Rhizome
Known Active Constituents
- Monoterpenes including geranial (
-citral) and neral (
-citral) and sesquiterpenes, including -sesquiphellandrene, -bisabolene, -curcumene, and -zingiberene. - Drying decreases monoterpenes and increases sesquiterpenes.
- Ginger also contains phenolic ketones, mainly gingerols and their derivative shogaols (1).
Mechanism/Pharmacokinetics
- In rats, 3 mg of 6-gingerol/kg was cleared within minutes from plasma; serum protein binding was 92.4% and total body clearance was 16.8 mL/minute/kg (2).
- Because pharmacologic effects have been demonstrated 3 hours after intravenous administration, gingerol may be sequestered in tissues or may be effective in extremely low concentrations (1).
- Gingerols inhibit lipoxygenase and affect prostaglandin synthetase activity in vitro. Ginger also appears to inhibit thromboxane synthetase and raise prostacyclin levels without increasing prostaglandin levels (1).
- One report examined the effect of 5 g of ginger daily for 7 days in seven women and found that mean thromboxane levels decreased by almost 37% (1).
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Clinical Trials
- Morning sickness
- A randomized, double-blind placebo-controlled trial in 70 women with nausea and vomiting of pregnancy compared ginger (1 g daily) to placebo for 4 days (3). Nausea severity was rated by a visual analog scale and number of vomiting episodes in the 24 hours before treatment compared with episodes during treatment. Visual analog scores and number of vomiting episodes decreased significantly in the ginger group, compared with the placebo group.
- In a double-blind crossover trial of 30 women with morning sickness (27 completed), each woman received ginger capsules (250 mg q.i.d.) or placebo for 4 days. After a 2-day washout period, each woman was crossed over to the other group for 4 days; 70.4% of the women preferred the ginger, which reduced both emesis and the degree of nausea (4).
- Postoperative nausea and vomiting
- Two of three studies showed a benefit of ginger. A double-blind, randomized study in 60 women undergoing major gynecologic surgery compared placebo with ginger (1 g p.o. 1.5 hours before surgery) or metoclopramide 10 mg (i.v. at induction of anesthesia); placebo pills and injections were used to preserve blinding (5). The incidence of nausea was significantly lower in the ginger-treated group than in the placebo group; the effect of metoclopramide was similar to ginger. The placebo group used significantly more antiemetic postoperatively than the treated groups.
- In a double-blind study that compared ginger (2g) and metoclopramide (10 mg) with placebo in 120 women undergoing laparoscopic gynecologic surgery, ginger equaled metoclopramide in preventing postoperative nausea and vomiting (6).
- Another placebo-controlled trial of 108 women undergoing gynecologic laparoscopic surgery (under general anesthesia, with preoperative diazepam) tested 500 mg and 1,000 mg of ginger given 1 hour before surgery. This dose was ineffective in reducing the incidence of postoperative nausea and vomiting (7).
- Chemotherapy-induced nausea and vomiting
- A small trial of 11 patients who regularly experienced nausea after taking 8-MOP before photophoresis found that ginger (1590 mg 30 minutes before 8-MOP) reduced nausea scores by two thirds (8).
- Motion sickness
- A placebo-controlled trial of eighty naval cadets unaccustomed to heavy seas found that ginger (1 g every hour for 4 hours) reduced the number of vomiting episodes and cold sweats but did not significantly reduce nausea or vertigo (9).
- Seven seasickness treatments, including ginger, were compared in 1,741 volunteers embarking on a whale safari in Norway (10). Medications were cinnarizine 25 mg; cinnarizine 20 mg with domperidone 15 mg; cyclizine 50 mg; dimenhydrinate 50 mg with caffeine 50 mg; ginger 250 mg (Zintona); meclizine 12.5 mg with caffeine 50 mg; and scopolamine 0.5 mg. Vomiting and retching were endpoints. At least some seasickness was reported by 18.2% to 26.8% of the participants. Questionnaires were returned by 1,489 volunteers (85.5%); there was no significant difference among treatments. The lack of a placebo control makes this trial difficult to interpret.
- Studies in preventing laboratory-induced motion sickness have been mixed. In one study, 36 undergraduates ingested capsules of dimenhydrinate, powdered ginger, or a placebo herb and then were blindfolded and placed in a tilted rotating chair for whichever of the following came first: 6 minutes, emesis, three triplings in the magnitude of nausea, or pleas for freedom (11). None of the participants in the placebo and dimenhydrinate groups could stay in the chair for 6 minutes, but half of those in the ginger group did.
- Another laboratory study of eight volunteers found ginger more effective than placebo in controlling induced dizziness (12).
- However, another study of induced motion sickness in 28 volunteers compared three preparations of ginger (500 mg or 1,000 mg dried root or 1,000 mg fresh root) to scopolamine (0.6 mg p.o.) or placebo (13). Neither powdered nor fresh ginger prevented motion sickness. Disordered gastric motility and decreased gastric emptying (associated with motion sickness) were not significantly affected by ginger.
- Gastroduodenal motility
- The effect of ginger extract (2 × 100 mg) on gastroduodenal motility was assessed by stationary manometry in 12 healthy volunteers (14). Oral ginger improved gastroduodenal motility in the fasting state and after a standard test meal.
- Osteoarthritis
- A double-blind, controlled crossover study in patients with osteoarthritis of the hip or knee tested ginger extract against ibuprofen or placebo (each given for 3 weeks with a 1-week washout period between treatments) (15). Acetaminophen use was allowed if needed. There was no difference between ginger and placebo; ibuprofen improved a visual analogue scale of pain and the Lequesne index. No serious adverse events occurred.
Animal/In Vitro
- Ginger prevents emesis in several species of animals (2).
- Cholesterol-lowering effects, cholagogic effects, hepatoprotective effects, decreased gastric secretion, and inhibition of gastric lesions have been demonstrated in animal studies (1).
- Shogaol has antitussive effects in animals.
- In vitro, ginger extracts demonstrate potent antioxidant effects; inhibit DNA damage induced by lipid peroxidation; and demonstrate modest antibacterial, antifungal, molluscicidal, ascaricidal, and antirhinoviral activity (1).
Other Claimed Benefits/Actions
- Arthritis
- Coughing
- Congestion
- Headaches
- Low back pain (injected)
- Diarrhea
- Suppressed menses
- Indigestion
- Burns, aches, pains, bruises, and cysts (topical)
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Adverse Reactions
- Dyspepsia
- Bezoar
- A few cases of bezoar have been reported; most cases involved the consumption of preserved ginger by children or the elderly (1).
Drug Interactions
- Sulfaguanidine: In rats, ginger enhances absorption of sulfaguanidine up to 150% (1).
Pregnancy/Lactation
See questions and answers
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Q: Is it safe to use ginger during pregnancy?
A: Some herbalists warn against using ginger during pregnancy. Although useful for morning sickness, ginger has traditionally been used for "suppressed menses" and may have abortifacient properties. This effect has not been shown in humans. Thromboxane synthetase inhibition has been demonstrated in vitro, but clinical trials show no effect (see next question).
In a double-blind, placebo-controlled crossover trial of ginger for nausea and vomiting of pregnancy in 30 women, one patient experienced a spontaneous abortion; another underwent induced abortion for non-medical reasons. Three patients were excluded from analysis. Twenty-five patients went to term, and all infants born were normal in terms of appearance, birthweight, and Apgar scores (4).
Although the cautious may choose to avoid large doses (greater than 1,000 mg/day) in pregnancy, there appears to be no harm in using smaller doses. Ginger is such a common ingredient in Asian cooking that it is unlikely to cause harm. Doses used medicinally are not much higher than doses received through food.
Q: Does ginger increase bleeding time?
A: No, at least not in usual doses. No cases of ginger-related bleeding have been reported, and this is one of the very few herbs for which platelet function tests have been done. Although ginger is a potent thromboxane synthetase inhibitor in vitro, clinical studies are reassuring. The first of these, a placebo-controlled crossover trial, administered 2 g of dried ginger to eight male volunteers; platelet function and bleeding time was assessed immediately before, 3 hours after, and 24 hours after ingestion. Ginger did not affect bleeding time, platelet count, or platelet function (16).
Very high doses of dried ginger, however, may affect platelets. A controlled trial tested a single dose of placebo against 10 g powdered ginger in 20 patients with coronary artery disease; ginger significantly reduced adenosine diphosphate (ADP)- and epinephrine-induced platelet aggregation (17). Another study in the same publication tested 4 g powdered ginger daily for 3 months in 10 to 30 patients with coronary artery disease (the number is not clear from the report); this dose of ginger had no effect on ADP- and epinephrine-induced platelet aggregation; lipids and glucose were also unaffected (17).
Another crossover trial in 18 healthy volunteers (including 9 women) compared the effect of placebo, 15 g raw ginger root, or 40 g cooked stem ginger, each given for 2 weeks (18). There was no significant effect of either dose on platelet cyclooxygenase activity, assessed by ex vivo maximally stimulated thromboxane B2 production.
In summary, although very high doses of dried ginger may reduce platelet aggregation, culinary use and ordinary medicinal use do not appear to affect bleeding.
Q: What is "ginger paralysis"?
A: Ginger preparations contaminated with tri-O-tolyl phosphate were responsible for a significant number of fatalities and cases of paralysis in the United States in 1930. There is nothing in ginger that causes this effect.