Summary

Ginger is an ancient herb used worldwide for its many health benefits. Ginger use widely varies by region, but it’s mostly used to add flavor to food and drink. It can also be used to cure nausea, and stomach upset. Different cultures use ginger in many different ways. The western world uses ginger to aid digestive and respiratory health. It can also be used to strengthen the immune system. Ginger is a good source of potassium, magnesium, and vitamin B6. One ounce of ginger contains about 20 calories. Ginger can be used by pregnant women to relieve nausea and vomiting. Ginger is available in chewable tablet, tea, capsule, and liquid extract form.

Description

Medicinal Parts

The medicinal part is the root.

Flower and Fruit

The flower grows directly from the root and terminates in a long, curved spike. A white or yellow flower grows from each spike.

Leaves, Stem, and Root

Ginger is a creeping perennial on a thick tuberous rhizome, which spreads underground. In the first year, a green, erect, reedlike stem about 60 cm high grows from this rhizome. The plant has narrow, lanceolate to linear-lanceolate leaves 15 to 30 cm long, which die off each year.

Characteristics

The fracture is short and fibrous. The odor and taste are characteristic, aromatic, and pungent.

Habitat

The plant is indigenous to southeastern Asia, and is cultivated in the U.S., India, China, the West Indies, and tropical regions.

Production

Ginger root consists of the peeled, finger-long, fresh or dried rhizome of Zingiber officinale.

Actions & Pharmacology

Compounds

Volatile oil (2.5-3.0%): chief components vary greatly, depending upon country of origin: (-)-zingiberene and ar-curcumene, beta-bisabolene and ar-curcumene, neral and geranial, D-camphor, beta-phellandrene, geranial, neral and linalool, (E)-alpha-farnesene, important as aroma carrier zingiberol (mixture of cis- and trans-beta-eudesmol)

Aryl alkanes

Gingerols: chief components [6]-Gingerol (pungent substances), [8]-Gingerol, [10]-Gingerol

Shogaols: chief components [6]-shogaol (pungent substane), [8]- shogaol, [10]- shogaol (artifacts formed during storage, arising from the Gingerols)

Gingerdiols

Diarylheptanoids: including among others, Gingerenone A and B

Starch (50%)

Effects

Ginger is primarily used for nausea and vomiting, dyspepsia, and motion sickness. Studies conducted in vitro and in animal models have elicited physiological effects related to a number of the compounds found in the Ginger rhizome. Among these are antiemetic, anti-inflammatory, antimicrobial, antioxidant, antilipid, antitumor, and cardiotonic effects. The root of Zingiber officinale has also shown immune-system stimulation and platelet aggregation-inhibitory activity. Other studies show that Ginger root is positively inotropic and antithrombotic, and promotes secretion of saliva, gastric juices and bile.

Antiemetic Effects

Ginger's antiemetic effects are attributed to the Gingerols and shogaols present in the rhizome of Zingiberis officinale. In contrast to most antiemetic medications that act on the CNS, the antiemetic effect of Ginger is thought to be due to local gastrointestinal actions: Ginger stimulates the flow of saliva, bile, and gastric secretions (Mowrey & Clayton, 1982); it suppresses gastric contractions, raises the tone of the intestinal muscles, and increases peristalsis (Bisset, 1994; Iwu, 1993). The mechanism of action is not due to a nystagmus response or vestibular stimulation (Holtmann, 1989). Various fat-soluble components of Ginger, such as galanolactone, have demonstrated antagonism of serotonin receptor sites (Huang, 1991). This latter mechanism may be responsible for some of Ginger's antiemetic effects as well as antispasmodic effects on visceral and vascular smooth muscle. Ginger inhibited serotonin-induced diarrhea (Huang, 1990).

Anti-Inflammatory Effects

The anti-inflammatory effect of Ginger is thought to be due to inhibition of cyclooxygenase and 5-lipoxygenase, resulting in reduced leukotriene and prostaglandin synthesis (Kiuchi, 1992; Srivastava & Mustafa, 1992). A component of Ginger, [6]-Gingerol, caused a significant reduction in 12-0-tetradecanoyl-phorbol-13 acetate (TPA)-induced ear inflammation compared to mice treated with TPA only (Park et al, 1998).

Antilipid Effects

Ginger significantly improved serum lipid parameters and reduced degree of atherosclerosis compared with no treatment in albino rabbits fed a high-cholesterol diet (Bhandari et al, 1998). Significant improvements in serum lipid parameters were observed in albino rats fed a normal diet supplemented with 0.5% Ginger for 4 weeks compared to untreated controls (Ahmed & Sharma, 1997).

Antimicrobial Effects

A sesquiterpene of Ginger may have antirhinoviral efficacy based on in vitro results. Zerumbone, a sesquiterpene isolated from Zingiber aromaticum and Z zerumbet, demonstrated in vitro inhibitory effects on human immunodeficiency virus (Dai et al, 1997). Two components of Ginger, 8-Gingerol and 10-Gingerol, demonstrated antibacterial activity against Bacillus subtilis and Escherichia coli K-12 in vitro (Yamada et al, 1992). Ginger has also shown antischistosomal activity. In mice, Gingerol (5 ppm) abolished the infectivity of Schistosoma mansoni miracidia and cercariae (Adewunmi et al, 1990).

Antimigraine Effects

In a study of phytochemicals, Ginger (Zingiber officinale) was rated as possibly useful for the treatment and prophylaxis of headaches. Mechanisms of headache amelioration of Ginger may include its inhibition of thromboxane production and inhibition of free radicals formed in the arachidonic acid cascade. Ginger decreases platelet aggregation and is a potent inhibitor of prostaglandins, which enhance release of substance P from trigeminal fibers (opiates inhibit substance P release) (Laurinaitis, 1995).

Antioxidant Effects

Cassumunin A demonstrated potent antioxidant activity and is a complex curcuminoid isolated from Zingiber cassumunar (Masuda et al, 1997). In rat liver microsomes, zingerone, from Ginger rhizomes, inhibited lipid peroxidation at high concentrations (greater than 150 micromoles) (Reddy & Lokesh, 1992).

Antithrombotic Effects

Preliminary studies have reported an antithrombotic effect for Ginger root, related to a reduction in production of thromboxane A2 and inhibition of platelet aggregation (Verma et al, 1993; Srivastava & Mustafa, 1989a). Subsequent studies of Ginger in therapeutic doses in healthy subjects and patients with coronary heart disease (CHD) were not able to confirm these results (Bordia et al, 1997; Janssen et al, 1996) although a large single dose (10 g) in CHD patients did significantly reduce platelet aggregation induced by adenosine diphosphate and epinephrine (Bordia et al, 1997).

Cardiotonic Effects

Gingerols and shogaols prepared from Zingiber officinale imparted positive inotropic effects on isolated guinea pig atria in an early study (Shoji et al, 1982). In another animal study (guinea pig), 6 and 8-shogaol had approximately equivalent inotropic effects as 8-Gingerol (Yamahara et al, 1995). Gingerol isolated from Zingiber officinale accelerated Ca(2+)-pumping rate in a concentration-dependent manner in cardiac sarcoplasmic reticulum (Kobayashi et al, 1987).

Immune System Effects

Increased secretions of interleukin-1 beta, interleukin-6, and granulocyte-macrophage colony-stimulating factor were demonstrated in human peripheral blood mononuclear cells in vitro in the presence of a low concentration of Zingiberis rhizoma extract (Chang et al, 1995).

Motion Sickness Effects

Ginger may have positive effects with motion sickness symptoms although the results of controlled studies are inconsistent. The adverse effects profile of Ginger is more favorable than those of other motion sickness preparations. No significant difference in symptoms occurred when results were tested within 1 hour (or less) of dosing in 1 study; however, in another study, differences between Ginger and placebo were greatest at 4 hours post ingestion (Schmid, 1994).

Postoperative Nausea and Vomiting Effects: Results from randomized, placebo-controlled, double-blind studies are conflicting (Visalyaputra et al, 1998). Comparative studies report statistically significant improvement in symptoms compared to placebo and similar efficacy compared to metoclopramide.

Clinical Trials

Chemotherapy-Induced Nausea

Forty-eight gynecologic cancer patients were enrolled into a randomized, double-blind crossover study to determine whether ginger has an antiemetic effect in cisplatin-induced emesis. All subjects were randomly allocated to a regimen A or regimen B in their first cycle of the study. All patients received standard antiemetics in the first day of cisplatin administraton. In regimen A, capsules of ginger root powder were given orally 1 g/day for 5 days, starting on the first day of chemotherapy. In regimen B, placebo was given on the first day and metoclopramide was given orally thereafter for 4 days. The patients were then crossed over to receive the other antiemetic regimen during their next cycle of chemotherapy. No significant differences were found between the treatment groups, indicating that the addition of ginger to a standard antiemetic regimen has no advantage in reducing nausea in the acute phase of cisplatin-induced emesis (Manusirivithayaet al, 2004).

Motion Sickness

One double-blind, randomized, non-placebo controlled study compared the effectiveness of Ginger and six other commonly used nonherbal drugs (scopolamine, dimenhydrinate with caffeine, cyclizine, cinnarizine, cinnarizine with domperidone, and meclizine with caffeine) in 1,489 participants during whale-watching voyages off the coast of Norway. About 78% of those who took 500 mg of Ginger root 2 hours prior to a boat trip were symptom-free for the 6-hour duration. The incidence of severe vomiting did not differ in a statistically significant way between Ginger and any of the other test groups (Schmid, 1994).

In an earlier, double-blind, randomized, placebo-controlled study of 80 naval cadets (median age 17 years) unaccustomed to sea travel, powdered Ginger root 1 g produced better control of symptoms (nausea, vomiting, vertigo, cold sweating) than placebo throughout the 4-hour test period. For individual symptoms of vomiting and cold sweating, Ginger was statistically superior to placebo (p<0.05); there was no significant difference for nausea and vertigo. The difference in total symptom scores achieved statistical significance four hours post ingestion (p<0.05). No adverse effects were attributed to Ginger (Grontved et al, 1988).

Nausea and Vomiting

A comprehensive review of published clinical and experimental data on Medline up to the end of December 2003, in addition to expert consultations, found indications to suggest that Ginger has antiemetic properties, with definitive evidence only for its ability to alleviate pregnancy-induced nausea and vomiting. For all other uses as an antiemetic, including for postoperative nausea and vomiting and for motion sickness, the evidence for Ginger is insufficient, the reviewers concluded. The review also looked at other uses for Ginger (Chrubasik, 2004).

In a study evaluating oral treatment of pregnancy-induced nausea with 125 mg Ginger extract 4 times daily (equivalent to 1.5 g dried Ginger daily) for 4 days compared to placebo (n=120), no differences in birth weight, gestational age, Apgar scores, or congenital abnormalities were observed in infants born from subjects who had consumed Ginger compared to the general population of infants born at the Royal Hospital for Women from 1999 to 2000. Birth defects observed were similar to the general population and were considered minor (Willetts et al, 2003).

Oral Ginger 1 g daily for 4 days was significantly more effective than placebo in the treatment of pregnancy-induced nausea and vomiting in women of less than 17 weeks gestation in a randomized, double-blind, placebo-controlled trial (n=70). Severity of nausea (visual analog and Likert scales) and number of episodes of vomiting was recorded 24 hours prior to treatment and also during treatment. Severity of nausea and episodes of vomiting decreased significantly with supplementation compared to placebo (p=0.014 and p=0.001, respectively). Patients in the group that received Ginger reported mild abdominal discomfort, diarrhea, and heartburn. No adverse effects on the outcome of the pregnancies were demonstrated in the treatment group (Vutyavanich et al, 2001).

In a double-blind, placebo-controlled study involving 120 females that underwent gynecologic outpatient surgery, the participants were randomly given either 1 g of powdered Ginger root or 10 mg of metoclopramide orally and evaluated for incidence of postoperative nausea and vomiting. Ten percent of the patients in the Ginger group had one or more episodes of vomiting; 17.5% of the metoclopramide arm and 22.5% of the placebo group had one or more episodes of vomiting. Of the Ginger group, 15% required antiemetic treatment compared to 32.5% of the metoclopramide group and 37.5% of the placebo group. The authors concluded that the Ginger group had a statistically significant lower incidence of nausea and vomiting when compared to placebo (Phillips, 1993).

Osteoarthritis and Rheumatoid Arthritis

Evidence for Ginger to treat osteoarthritic or other pain is equivocal, according to a comprehensive review of clinical and experimental data. While there is insufficient evidence to confirm that Ginger actually alleviates clinical osteoarthritis or other pain, constituents in the root clearly do interfere with the inflammatory cascade and certain pain receptors. Further studies may not only provide backup for Ginger's efficacy for osteoarthritis pain but also establish an optimum daily dosage for treating this common ailment (Chrubasik, 2004).

In an earlier study, Ginger proved to be no more effective than placebo in a randomized, placebo-controlled, crossover study comparing Ginger, ibuprofen, and placebo in the treatment of osteoarthritis. Significant improvement was only achieved with ibuprofen (400 mg) as evidenced by the visual analog scale (VAS; p<0.0001) and the consumption of rescue medication (acetaminophen; p<0.01) (Bliddal et al, 2000).

In a preliminary open study, 74% of patients with rheumatoid arthritis (n=28) and 55% of patients with osteoarthritis (n=18) reported “marked” improvement in pain after taking powdered Ginger 1 to 2 g daily for up to 2.5 years. With regard to swelling, 59% of rheumatoid arthritis and 50% of osteoarthritis patients reported “marked” improvement. Ten patients with myalgias also reported pain relief with Ginger therapy. No adverse effects occurred. The results of this study are based solely on patient questionnaires; controlled, blinded studies are needed (Srivastava & Mustafa, 1992).

Platelet Aggregation

Powdered Ginger significantly inhibited platelet aggregation in a placebo-controlled study of 20 patients with coronary artery disease. Patients received powdered Ginger 10 g as a single dose. Ginger reduced adenosine diphosphate (ADP) and epinephrine-induced platelet aggregation (p<0.05). The platelet response appears to be dose dependent, as Ginger 4 g daily for 1.5 and 3 months did not exert any appreciable effect on platelet aggregation, fibrinogen, or fibrinolytic activity. All patients had a history of myocardial infarction greater than 6 months old; all were taking nitrates and aspirin. Aspirin was discontinued 2 weeks prior to the study (Bordia et al, 1997).

Raw Ginger root had no significant effect on platelet function in 18 healthy volunteers in a randomized, placebo-controlled, crossover study. Subjects received either raw Brazilian Ginger root 15 g, cooked stem Ginger 40 g, or placebo for 2 weeks. Subjects discontinued use of any medications for 1 month prior to the study. The mean decrease in thromboxane production was 1 ± 9% for Ginger root and 1 ± 8% for stem Ginger as compared to placebo (p=0.984). Mean thromboxane B2 production was unchanged (Janssen, 1996).

Indications & Usage

Approved by Commission E:

• Loss of appetite
• Travel sickness
• Dyspeptic complaints

Unproven Uses

In folk medicine, Ginger is used as a carminative, expectorant, and astringent.

Chinese Medicine

In China, Ginger is used to treat colds, nausea, vomiting, and shortness of breath.

Indian Medicine

Indian medicine uses include anorexia, dyspeptic symptoms, and pharyngitis.

Contraindications

Because of its cholagogic effect, the drug should not be taken in the presence of gallstone conditions except after consultation with a physician. Ginger may inhibit thromboxane synthesis and should not be used by patients who are at risk for hemorrhage (Fleming, 2000; Bracken, 1991).

Precautions & Adverse Reactions

No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages. Adverse reactions include minor gastrointestinal complaints such as gas, bloating, and heartburn.

It has been reported that administration of 6 g of dried powdered Ginger has been shown to increase the exfoliation of gastric surface epithelial cells in human subjects. It is postulated that this action may possibly lead to ulcer formation. Therefore, it is recommended that dosages on an empty stomach be limited to 6 g (Desai, 1990).

There have been reports that Ginger can cause hypersensitivity reactions resulting in dermatitis. Large overdoses can cause central nervous system depression and cardiac arrhythmias.

Pregnancy

Some experts suggest that Ginger should not be used in pregnancy or lactation (McGuffin et al, 1997). The German Commission E lists morning sickness associated with pregnancy as a contraindication, and the American Herbal Products Association lists pregnancy as a contraindication; however, no clinical evidence has been found to substantiate any harmful effects to mother or fetus. Most research provides evidence that Ginger can be used and is effective in the treatment of morning sickness (Vutyavanich et al, 2001; Fischer-Rasmussen et al, 1990). Ginger tea administered to pregnant Sprague-Dawley rats resulted in double the number of fetal losses compared to the control group (p<0.05). There were no gross morphologic malformations observed in the fetuses in the treatment group but fetuses in the treatment group were significantly heavier than control fetuses (Wilkinson, 2000).

Drug Interactions

Moderate Risk

Anticoagulants

Concurrent use may result in increased risk of bleeding. Clinical Management: The clinical significance of any effect Ginger may have on platelet aggregation is undetermined. Caution is advised if Ginger and an anticoagulant are taken concomitantly. Studies suggest that over 4 grams of dried or 15 grams raw Ginger root daily must be ingested in order to have any effect on blood coagulation.

Minor Risk

Antiplatelet agents, Low molecular weight heparins, thrombolytic agents

Concurrent use may result in increased risk of bleeding. Clinical Management: The clinical significance of any effect Ginger may have on platelet aggregation is undetermined. Caution is advised if Ginger and any of these agents are taken concomitantly. Studies suggest that over 4 grams of dried or 15 grams raw Ginger root daily must be ingested in order to have any effect on blood coagulation.

Overdosage

According to research, the LD50 of 6-Gingerol and 6-shogaol is set between 250 and 680 mg/kg. (Fulder & Tenne, 1991; Suekawa et al, 1984.) Toxicity tests in mice using a Ginger extract via lavage resulted in no mortality or adverse effects in doses up to 2.5 g/kg over a 7 day period. When the dose was increased to between 3 and 3.5 g/kg, a 10% to 30% mortality rate was reported (Macola, 1989.)

Overdosage may cause cardiac arrhythmia and CNS depression (Iwu, 1993).

Dosage

Mode of Administration

Comminuted rhizome and dry extracts for teas and other galenic preparations for internal use. The powdered drug is used in some stomach preparations.

How Supplied

• Capsules – 100 mg, 400 mg, 420 mg, 460 mg, 470 mg, 500 mg, 550 mg, 1000 mg
• Chewable Tablets – 67.5 mg
• Fluid Extract – 1:1
• Liquid – 1:4 Oil – 100%
• Tea Bags

Preparation

To prepare an infusion, pour boiling water over 0.5 to 1 g drug and strain after 5 minutes (1 teaspoonful = 3 g drug).

Daily Dosage:

• Antiemesis: Capsules/Powder – 0.5 to 2 g (Bisset,1994; Schmid et al, 1994)
• Chemotherapy-induced nausea and vomiting: All dosage forms – 1.5 g (Myer et al, 1995).
• Dysepsia: Capsules/Powder – 2 to 4 g/day
• Motion Sickness: Capsules/Powder – 1 g to be taken 30 minutes before travel; for continuing symptoms, 0.5 to 1 g every 4 hours (Muller & Clauson, 1997).
• Rheumatoid Arthritis and Osteoarthritis: Powder – 1 to 2 g/day (Srivastava & Mustafa, 1992).

Storage

Powdered Ginger root should be stored in a cool, dry place protected from light. Powdered Ginger should not be stored in plastic containers.

Literature