JoHealth.com

Introduction

Native to southern Asia, ginger is a 2- to 4-foot perennial that produces grass-like leaves up to a foot long and almost an inch wide. Ginger root, as it is called in the grocery store, actually consists of the underground stem of the plant, with its bark-like outer covering scraped off.
Ginger has been used as food and medicine for millennia. Arabian traders carried ginger root from China and India to be used as a food spice in ancient Greece and Rome, and tax records from the second century A.D. show that ginger was a delightful source of revenue to the Roman treasury. Presently, the annual production of ginger exceeds 2 million pounds.
Chinese medical texts from the fourth century B.C. suggest that ginger is effective in treating nausea, diarrhea, stomachaches, cholera, toothaches, bleeding, and rheumatism. Ginger was later used by Chinese herbalists to treat a variety of respiratory conditions, including coughs and the early stages of colds.
Ginger's modern use dates back to the early 1980s, when a scientist named D. Mowrey noticed that ginger-filled capsules reduced his nausea during an episode of flu. Inspired by this, he performed the first double-blind study of ginger. Germany's Commission E subsequently approved ginger as a treatment for indigestion and motion sickness.
One of the most prevalent ingredients in fresh ginger is the pungent substance gingerol. However, when ginger is dried and stored, its gingerol rapidly converts to the substances shogaol and zingerone. Which, if any, of these substances is most important has not been determined.

What Is Ginger Used for Today?

Ginger is used for the prevention and treatment of various forms of nausea. These include motion sickness, the nausea and vomiting of pregnancy (morning sickness), and post-surgical nausea.
Note: If you are pregnant or undergoing surgery, do not self-treat with ginger except under physician supervision.
Weak evidence suggests ginger might be helpful for osteoarthritis.
Ginger has been suggested as a treatment for numerous other conditions, including atherosclerosis, migraine headaches, rheumatoid arthritis, high cholesterol, burns, ulcers depression, impotence, and liver toxicity. However, there is negligible evidence for these uses.
In traditional Chinese medicine, hot ginger tea taken at the first sign of a cold is believed to offer the possibility of averting the infection. However, once more there is no scientific evidence for this use

What Is the Scientific Evidence for Ginger?

The evidence for ginger's effectiveness is mixed. It has been suggested that, in some negative studies, poor-quality ginger powder might have been used. In general, while most antinausea drugs influence the brain and the inner ear, ginger appears to act only on the stomach.

Motion Sickness

A double-blind placebo-controlled study of 79 Swedish naval cadets found that 1 g of ginger could decrease vomiting and cold sweating but without significantly decreasing nausea and vertigo. Benefits were also seen in a double-blind study of 36 individuals given ginger, dimenhydrinate, or placebo.
In addition, a double-blind comparative study that followed 1,489 individuals aboard a ship found ginger to be equally effective as various medications (cinnarizine, cinnarizine with domperidone, cyclizine, dimehydrinate with caffeine, meclozine with caffeine, and scopolamine). Another double-blind study found equivalent benefit of ginger at a dose of 500 mg every 4 hours and dimenhydrinate 100 mg every 4 hours in a group of 60 passengers aboard a ship. Similar results were also seen in a small double-blind study involving children.
However, a 1984 study funded by NASA found that ginger was not any more effective than placebo. Two other small studies have also failed to find any benefit. The reason for the discrepancy may lie in the type of ginger used, or the severity of the stimulant used to bring on motion sickness.

Nausea and Vomiting of Pregnancy

A double-blind placebo-controlled trial of 70 pregnant women evaluated the effectiveness of ginger for morning sickness. Participants received either placebo or 250 mg of powdered ginger 3 times daily for a period of 4 days. The results showed that ginger significantly reduced nausea and vomiting. No significant side effects occurred.
Benefits were also seen in a double-blind trial of 27 women.
Note: Ginger has not been proven safe for pregnant women.

Post-Surgical Nausea

A double-blind British study compared the effects of ginger, placebo, and metoclopramide in the treatment of nausea following gynecological surgery. The results in 60 women indicated that both treatments produced similar benefits as compared to placebo.
A similar British study followed 120 women receiving elective laparoscopic gynecological surgery. Whereas nausea and vomiting developed in 41% of the participants given placebo, in the groups treated with ginger or metoclopramide (Reglan) these symptoms developed in only 21% and 27%, respectively.
However, a double-blind study of 108 people undergoing similar surgery found no benefit with ginger as compared to placebo. Negative results were also seen in another recent study of 120 women.

Dosage

For most purposes, the standard dosage of powdered ginger is 1 to 4 g daily, divided up into 2 to 4 doses per day.
To prevent motion sickness, it may be best to begin treatment 1 or 2 days before the trip and continue it throughout the period of travel.

Safety Issues

Ginger is on the FDA's GRAS (generally recognized as safe) list as a food, and the treatment dosages of ginger are comparable to dietary usages. No significant side effects have been observed.
Like onions and garlic, extracts of ginger inhibit blood coagulation in test tube experiments. This has led to a theoretical concern that ginger should not be combined with drugs such as Coumadin (warfarin), heparin, Plavix (clopidogrel), Trental (pentoxifylline), or even aspirin. European studies with actual oral ginger taken alone in normal quantities have not found any significant effect on blood coagulation, but it is still possible that combination treatment could cause problems.
Safety in pregnant or nursing women, young children, or individuals with severe liver or kidney disease has not been established

Interactions You Should Know About

If you are taking strong blood-thinning drugs such as Coumadin (warfarin) heparin, Plavix (clopidogrel), Trental (pentoxifylline), or even aspirin, ginger might possibly increase the risk of bleeding problems.