Natural Products

Ginger

Zingiber officinale

Efficacy

• Indications with proven efficacy:
  None
• Indications with possible, but poorly documented efficacy - the use of this product cannot be recommended:
  Chemotherapy-induced nausea
  Morning sickness during pregnancy
  Motion sickness
  Postoperative nausea/vomiting in the absence of narcotic anesthesia or analgesia
  Vertigo
• Also used for these other indications, but with no proof of efficacy:
  Bacterial dysentery
  Baldness
  Dyspepsia
  Malaria
  Migraine
  Orchitis (testicular inflammation)
  Poisonous snake bites
  Rheumatoid arthritis/osteoarthritis
  Toothache

Security

• Risk of Drug Interactions: Moderate
• Adverse Effects: Not Frequent

What is it?

Ginger is a perennial plant native to South-West Asia that is now being cultivated in several tropical areas throughout the world. Its rhizome (root) is commonly used in cooking and is prized for its particular taste and fragrance. Ginger has been a staple in traditional Asian medicine for hundreds of years. It is used as a digestive to control indigestion, bloating and stomach ache.

Rhizomes contain between 1 and 3% of volatile oils and it is these oils that are behind the pharmacological properties and characteristic fragrance of ginger. As for its medicinal use, rhizomes are ingested fresh or dried or taken as an oral capsule.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) or homeopathic medicine number (DIN-HM) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plants content varies naturally from plant to plant – just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

Does it work?

There is no evidence that ginger is effective in any indication. However it is used to treat certain medical conditions in which it may be of some benefit:

• Chemotherapy-induced nausea:
  Doses from 2000 to 4000 mg of dried root daily have been used. A ginger tea has also been used.
• Morning sickness during pregnancy:
  A dose of 250 to 500 mg of dried root 4 times daily has been used in studies. However, the safety of ginger during pregnancy is controversial.
• Motion sickness:
  The recommended dose is 1000 mg of dried root 30 minutes to 4 hours before departure. The dosing range is 500 to 1000 mg as needed (not to exceed 4000 mg per day).
• Postoperative nausea/vomiting in the absence of narcotic anesthesia or analgesia:
  For prevention of postoperative nausea and vomiting 1000 mg of dried root is given 1 hour before induction of anesthesia. However, ginger does not seem to be effective when narcotics have been used.
• Vertigo:
  A dose of 1000 mg dried root may reduce symptoms of vertigo, including nausea.

There is insufficient reliable information to conclude that ginger is effective in any other indication.

Is it safe?

• Ginger is not associated with any severe toxicity. But some light adverse effects are possible: abdominal discomfort, heartburn, diarrhea, mouth irritation and some individuals may experience a skin reaction upon contact. Very large amounts of ginger can apparently cause cardiac arrhythmias and drowsiness. Food amounts are usually associated with no adverse effects.
• Pregnant women should limit their intake of ginger to typical food amounts since large quantities are thought to promote spontaneous abortions. Current data are insufficient to conclude to its safety during breast-feeding. Lactating women should avoid using amounts greater than those found in foods.
• Individuals with gallstones should not use ginger except after medical evaluation.
• Large amounts of ginger can apparently "thin the blood" (antiplatetlet effect). To reduce the rusk of bleeding, people who take anticoagulants or antiplatelet agents should avoid excessive amounts of ginger. Before taking ginger, check with your pharmacist to make sure that there are no interactions with your regular medication.

Clinical notes

• Ginger has been used as a spice for centuries. Current information about this product leads us to believe that it may be useful as a digestive aid and to prevent motion sickness. However, further research is required to clearly establish its medicinal potential in other clinical situations.

References

1. Blumethal M et al. The Complete German Commission E monographs, 1998
2. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2007
3. Lininger S. et Al. The Natural Pharmacy, Prima Health, 1998
4. Peirce, Andrea. Practical Guide to Natural Medicines, APha, 1999
5. Facts & Comparisons, The Lawrence review of natural products, 1998
6. Passeportsanté.net. Gingembre. http://www.passeportsante.net
7. Rotblatt M. et Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002
8. Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79
9. Barnes J. et Al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002