Ginger is a popular seasoning for foods in many different cuisines.
In China and Southeast Asia where it probably originated, it has also been put to a range of medicinal purposes. It is considered good for the digestion and beneficial against congestion.
One of our favorite home remedies for colds is a cup of ginger tea: Peel a piece of fresh ginger root about the size of your thumb and grate it into a cup.
Pour boiling water over it and steep for five minutes. Strain the liquid into another cup, sweeten to taste with honey, and enjoy the spicy flavor. It does make one feel better, at least for an hour or two.
More research has been conducted on the ability of ginger to prevent motion sickness than on any other aspect of its use. The part of the plant used is the rhizome (“root”).
The primary active ingredients in ginger are the “pungent principles” that give the plant its special aroma and flavor. These are gingerols and shogaols, gingerdiones and zingerone.
The composition of the volatile oil differs in roots from different locations, however. Zingiberene, ar-curcumene, and bisabolene usually predominate, but gingers from Australia and Japan contain more geranial (citral a) and neral (citral b), with the Australian ginger also carrying camphor and b-phellandrene.
Chinese fishermen have known for centuries that ginger can stave off seasickness. In the last few decades, this has been confirmed by scientific studies.
In one, ginger (administered in capsules of 940 mg), Dramamine (100 mg), and a placebo (chickweed) were compared for their ability to keep susceptible subjects from becoming nauseated while seated on a spinning chair.
Ginger did better than Dramamine, surprising many physicians. Not all of the subsequent research has led to the same conclusions, but several investigations support these findings.
Another study took place on a passenger cruise ship on rough seas. In this double-blind study, ginger (500 mg every four hours) was equally effective as Dramamine (100 mg every four hours).
Ginger proved significantly better than placebo for a group of naval cadets on a sailing ship in heavy seas and also proved its value in a test conducted among tourist volunteers on a whale-watching cruise.
It is believed that ginger exerts its antinausea properties directly on the gastrointestinal tract, rather than through the central nervous system as most of the familiar motion-sickness medications do.
Ginger has been studied for its ability to prevent nausea and vomiting in other situations.
In two separate investigations of women undergoing gynecological surgery, ginger given before the operation reduced postoperative nausea significantly compared to placebo. The prescription drug metoclopramide (Reglan) was equivalent to ginger in effectiveness.
This property may explain the popularity of ginger ale as a home remedy for nausea in America decades ago, when the beverage actually contained more than trace amounts of ginger. If you can find real ginger ale, 12 ounces is enough to prevent motion sickness and presumably may help ease nausea from other causes as well.
Ginger has also been used in folk medicine for indigestion and to pep up the appetite and get saliva flowing.
It is reputed to prevent flatulence if included in a meal, such as beans, that might cause gas.
In animal studies, shogaol increases the activity of the digestive tract when it is given by mouth.
Extracts containing shogaol and the gingerols can make animal’s hearts beat more strongly (cardiotonic) and reduce pain and fever.
Animal studies also show that these compounds can suppress coughs.
Ginger is known to block to some extent the manufacture of prostaglandins in the body. It is reputed to lower cholesterol and keep blood platelets from clumping together.
In addition, a closely related herb, Z. capitatum, which is sometimes used in place of ginger, contains an interferon-like compound that can stimulate immune system activity.
Minimum dose for an adult is 250 mg. Doses of 500 mg and 940 mg have been used in clinical trials for motion sickness.
For motion sickness, ginger should be taken at least half an hour before departure. It is most effective at preventing nausea and does not work well at calming it once it has begun.
The dose may be repeated every four hours, to a maximum adult dose of approximately 4 gm a day. Candied or fresh ginger might be substituted, but the dose could be difficult to calculate.
German authorities recommend that pregnant women avoid ginger. Despite its ability to prevent nausea, they state that the herb should not be used for morning sickness.
Components of ginger triggered mutations in bacteria in some tests. In addition, ginger’s ability to prevent prostaglandin synthesis and possibly increase bleeding could make it a dangerous drug for a woman in labor.
Ginger is said to increase bile acid secretion. This is the reason people with gallstones or gallbladder disease are advised to avoid the herb unless supervised by a doctor.
Like many commonly used culinary herbs, ginger has very few side effects. In clinical trials, heartburn was reported rarely. A few people may develop an allergy to ginger, but this is uncommon.
Ginger is said to increase the absorption of other drugs taken with it, but this property does not appear to have been studied extensively, if at all.
Ginger can prolong the amount of time an animal sleeps when given a barbiturate. Because the herb has no detectable effects on the central nervous system itself, the most logical explanation is that it increases the absorption of the sleeping pill.
Because ginger inhibits prostaglandin synthesis and reduces platelet aggregation, caution should be exercised in combining it with other medications that prevent clotting, such as Coumadin, aspirin, Plavix, or Ticlid. The combination could result in unexpected bleeding.