As so many other mothers have done over the years, my mom always gave us kids ginger ale to soothe away the grumblings of an upset stomach. The use of this time-honored home remedy actually has been validated by scientific testing; in fact, few other foods or spices have been documented as thoroughly for their medicinal value as has ginger, the fresh or dried root (rhizome) of Zingiber officinale that is the predominant flavoring of ginger ale.
Ginger, the plant
The ginger family (Zingiberaceae) contains 1,300 species in fifty-three genera that are native to the Tropics and Subtropics and especially abundant in Indonesia. The genus Zingiber includes about 100 species of aromatic perennial herbs from East Asia and tropical Australia. (The generic name is derived from a Sanskrit word meaning “horn-shaped” referring to the protrusions on the rhizomes. In Z. officinale, the scaly rhizomes branch with thick, thumblike protrusions; divisions of the rhizome are known as “hands”.)
Ginger is an erect plant growing 1 to 4½ feet in height. The stem is surrounded by the sheathing bases of the two-ranked leaves. The clublike spikes of yellowish, purple-lipped flowers with showy greenish yellow bracts are rarely seen in cultivated plants.
Ginger plants are now cultivated for export in nearly every tropical and subtropical country in the world with arable land. Major world producers include Fiji, India, Jamaica, Nigeria, Sierra Leone, and China. The spice ginger, in both fresh and dried form, has become increasingly popular in the United States in recent years. Since 1990, the United States has imported an average of more than 4,000 metric tons per year from China, several Caribbean islands, Africa, Central America, Brazil and Australia. The best ginger I’ve ever tasted was organically grown in Hawaii.
Rooted in history
Ginger has been cultivated for so long that no one is sure where it originated. In China, dried ginger is first mentioned in the herbal attributed to the Divine Plowman Emperor Shen Nong, who lived about 2000 b.c. Mention of fresh ginger first occurs in two Chinese medical books published about a.d. 500. Ginger, also grown for millennia in India, reached the West at least 2,000 years ago. References to ginger are found in eleventh-century Anglo-Saxon leech (medical) books. (Physicians were called leeches because they used leeches for bloodletting.) Next to black pepper, ginger was the most popular spice in thirteenth-century England, and a pound of ginger was valued at the price of one sheep.
In China, fresh ginger and dried ginger have always been considered two different substances. One early herbalist even suggested that they must come from different plants. In Traditional Chinese Medicine (TCM), the fresh root, called sheng-jiang, is used to expel cold and toxins and relieve nausea, whereas the dried root, gan-jiang, is prescribed in cases of depleted yang, “cold” pain of the stomach and abdomen, diarrhea, cough, and rheumatism.
In India, fresh ginger has been used to treat nausea, asthma, cough, colic, heart palpitations, swellings, dyspepsia, loss of appetite and rheumatism. A popular nineteenth-century Indian remedy for cough and asthma consisted of the juice of fresh ginger with a little juice of fresh garlic, mixed with honey. To allay nausea, fresh gingerroot was mixed with a little honey topped off with a pinch of burnt peacock feathers. The powdered dried root was mixed to a paste with water and applied to the temples to relieve headache.
Europeans have long valued ginger tea as a remedy for digestive disturbances. For example, in The Family Herbal (1814), the English physician Robert Thorton recommends taking two or three cupfuls for breakfast to relieve gout, flatulence, or dyspepsia due to hard drinking. He believed that ginger works by promoting circulation through the “extreme” (that is, peripheral) blood vessels.
Modern studies support several of ginger’s traditional uses. Root extracts, as well as ginger in its fresh and dried forms, have been studied for their effectiveness in combating bacteria, fungi, convulsions, pain, ulcers, gastric secretion, tumors, spasms, and oxidative and allergic reactions. In some studies, the extracts used have been standardized to gingerol content, one of ginger’s pungent principles.
Animal experiments involving rats in both China and the West have shown that fresh ginger relieves pain and inflammation. In vitro studies have shown that it also inhibits oxidation, which has been linked to cancer risk, and the growth of microbes.
Ginger appears to benefit the circulatory system in several ways. A more potent anticoagulant than garlic or onion, it also lowers levels of cholesterol in the blood by reducing its absorption by the blood and liver. Studies by Japanese researchers further have shown that ginger lowers blood pressure by restricting peripheral blood flow. All these effects may lower the risk of cardiovascular disease.
Results of experiments testing ginger as a migraine treatment prompted by the long history of its use in Ayurvedic medicine for neurological disorders were inconclusive but promising. Additional studies are necessary.
A large number of studies have focused on ginger’s effect on digestion. In a Chinese study involving humans, a tea made with fresh ginger reduced gastric secretions for a few hours, then increased them for a longer period. Another Chinese study found that the dried root “strengthens” the stomach, stimulates both the stomach and intestines, and inhibits vomiting. A recent study showed that acetone and methanol extracts of ginger strongly inhibit the formation of stomach ulcers. Other studies have shown that gingerol counters liver toxicity by increasing bile secretion.
Of six clinical studies evaluating ginger’s effect on motion sickness, four European studies reported positive results while two American studies reported negative results. In an English study, thirty-six volunteers received either capsules containing 940 mg of dried ginger or dimenhydrinate, an antihistamine used in an over-the-counter antimotion-sickness product. When they were blindfolded and placed in a spinning chair for a maximum of 6 minutes, those who received the ginger capsules lasted an average of 5.5 minutes and those who took the antihistamine, 3.5 minutes, before becoming ill.
A double-blind, randomized, placebo-controlled trial tested ginger’s effectiveness in combating seasickness in eighty naval cadets unaccustomed to high seas. Those who took capsules of dried ginger experienced fewer cold sweats and less nausea than those who received the placebo.
Because half of all space shuttle crew members experience motion sickness, NASA has also been interested in ginger as a potential preventive. However, a 1988 NASA-sponsored study concluded that neither a capsule containing 0.5 to 1 g of dried powdered ginger taken two hours before testing nor 1 g of minced fresh ginger taken thirty minutes before testing was effective in preventing motion sickness in forty-two volunteers tested in a spinning chair. It’s worth noting, however, that practitioners of TCM recommend a dosage of 3 to 9 g of fresh gingerroot or ginger juice for motion sickness and don’t use the dried root at all for this purpose.
Ginger is believed to reduce nausea by increasing digestive fluids and absorbing and neutralizing toxins and stomach acid. Limited studies have suggested that ginger may reduce morning sickness as well as nausea after surgery. Both uses require a physician’s supervision. Clearly, further studies are needed.
To make a cup of ginger tea, pour 1 cup of boiling water over five or six thin slices of fresh gingerroot or ½ teaspoon dried, powdered root. Steep, covered, for 30 minutes. Herbalists recommend a cup of dried ginger tea every couple of hours to allay early cold or flu symptoms or relieve mild nausea or diarrhea.
In Germany, ginger products are approved for treatment of indigestion and prevention of motion sickness. The average recommended daily dose, not to be exceeded, is 2 g of the dried rhizome. Persons with gallbladder disease are advised to avoid ginger altogether.
Both fresh and dried roots are official drugs of the modern Chinese pharmacopoeia, as are a liquid extract and a tincture. An ingredient of as many as half of all herbal prescriptions in China, ginger is believed to decrease the toxicity of other ingredients. In the United States, ginger tinctures and capsules of powdered ginger are available in health-food stores. Herbalists recommend 10 to 20 drops of ginger tincture in a glass of water with meals to counteract indigestion or relieve early cold or flu symptoms. Enteric-coated capsules, which dissolve in the small intestine, may be substituted if tinctures cause a burning sensation in the stomach. Take as directed on the label.
Steven Foster is an author, photographer and consultant, specializing in medicinal plants.
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