The characteristic odor and flavor of ginger root is caused by a mixture of zingerone, shogaols and gingerols, volatile oils that compose about one to three percent of the weight of fresh ginger. In laboratory animals, the gingerols increase the motility of the gastrointestinal tract and have analgesic, sedative, antipyretic and antibacterial properties.[3]
Ginger contains up to three percent of a fragrant essential oil whose main constituents are sesquiterpenoids, with (-)-zingiberene as the main component. Smaller amounts of other sesquiterpenoids (β-sesquiphellandrene, bisabolene and farnesene) and a small monoterpenoid fraction (β-phelladrene, cineol, and citral) have also been identified.
The pungent taste of ginger is due to nonvolatile phenylpropanoid-derived compounds, particularly gingerols and shogaols, which form from gingerols when ginger is dried or cooked. Zingerone is also produced from gingerols during this process; this compound is less pungent and has a spicy-sweet aroma.[4] Ginger is also a minor chemical irritant, and because of this was used as a horse suppository by pre-World War I mounted regiments for figging.
Ginger has a sialagogue action, stimulating the production of saliva, which makes swallowing easier.
Medicinal uses
The medical form of ginger historically was called “Jamaica ginger”; it was classified as a stimulant and carminative, and used frequently for dyspepsia and colic. It was also frequently employed to disguise the taste of medicines. Ginger is on the FDA’s ‘generally recognized as safe‘ list, though it does interact with some medications, including warfarin. Ginger is contraindicated in people suffering from gallstones as the herb promotes the release of bile from the gallbladder.[5] Ginger may also decrease joint pain from arthritis, though studies on this have been inconsistent, and may have blood thinning and cholesterol lowering properties that may make it useful for treating heart disease.[6]
Diarrhea
Ginger compounds are active against a form of diarrhea which is the leading cause of infant death in developing countries. Zingerone is likely to be the active constituent against enterotoxigenic Escherichia coli heat-labile enterotoxin-induced diarrhea.[7]
Nausea
Ginger has been found effective in multiple studies for treating nausea caused by seasickness, morning sickness and chemotherapy,[8] though ginger was not found superior over a placebo for post-operative nausea.
Folk medicinal uses
A variety of uses are suggested for ginger. Tea brewed from ginger is a folk remedy for colds. Three to four leaves of Tulsi taken along with a piece of ginger on an empty stomach is an effective cure for congestion, cough and cold. Ginger ale and ginger beer have been recommended as “stomach settlers” for generations in countries where the beverages are made, and ginger water was commonly used to avoid heat cramps in the US. Ginger has also been historically used to treat inflammation, which several scientific studies support, though one arthritis trial showed ginger to be no better than a placebo or ibuprofen.[6] Research on rats suggests that ginger may be useful for treating diabetes.[9][10]
- Local uses
In the West, powdered dried ginger root is made into capsules and sold in pharmacies for medicinal use.
- In Burma, ginger and a local sweetener made from palm tree juice (Htan nyat) are boiled together and taken to prevent the flu.
- In China, a drink made with sliced ginger cooked in sweetened water or a cola is used as a folk medicine for the common cold.[11]
- In the Congo, ginger is crushed and mixed with mango tree sap to make tangawisi juice, which is considered as a universal panacea.
- In India, ginger is applied as a paste to the temples to relieve headache and consumed when suffering from the common cold, people use ginger for making tea, in food etc.
- In Indonesia, a type of ginger known as Jahe is used as a herbal preparation to reduce fatigue, reducing “winds” in the blood, prevent and cure rheumatism and controlling poor dietary habits.
- In the Philippines a traditional health drink called “salabat” is made for breakfast by boiling chopped ginger and adding sugar; it is considered good for a sore throat.
- In the United States, ginger is used to prevent motion and morning sickness. It is recognized as safe by the Food and Drug Administration and is sold as an unregulated dietary supplement.
Phytochemicals
Cranberries are a source of polyphenol antioxidants, phytochemicals under active research for possible benefits to the cardiovascular system, immune system and as anti-cancer agents.[8][9]
Cranberry juice contains a chemical component, a high molecular weight non-dializable material (NDM), as noted above, that is able to inhibit and even reverse the formation of plaque by Streptococcus mutans pathogens that cause tooth decay.[10][11] Cranberry juice components also show efficacy against formation of kidney stones.[12][13]
Raw cranberries and cranberry juice are abundant food sources of the anthocyanidin flavonoids, cyanidin, peonidin and quercetin.[14][15] These compounds have an unknown effect on human health, but are powerful against human cancer cells in vitro. Their effect in humans, however, is unproven, showing poor absorption into human cells and rapid elimination from blood.
Since 2002, there has been an increasing focus on the potential role of cranberry polyphenolic constituents in preventing several types of cancer.[16][17][18][19][20] In a 2001 University of Maine study that compared cranberries with twenty other fruits, cranberries had the largest amount of both free and total phenols, with red grapes at a distant second place.[21] Cranberry tannins have anti-clotting properties and may reduce urinary tract infections and the amount of dental plaque-causing oral bacteria, thus being a prophylaxis for gingivitis.[22]
Anti-adhesion properties
There is potential benefit of cranberry juice consumption against bacterial infections in the urinary system. Research shows that an effect occurs from a component of the juice inhibiting bacterial attachment to the bladder and urethra.[23] [24] [25]
Although promising for anti-bacterial activity, long-term consumption of cranberry juice has only limited evidence for beneficial effects against urinary tract infections in women.[26] Similar applications have not been successfully proved in other clinical trials of consuming cranberry juice or tablets by people with spinal cord injury associated with bladder catheterization, neurogenic bladder or infrequent urination, any of which may be associated with increased susceptibility to bacterial infections.[27][28][29]
Current and completed clinical trials
In April 2004, the French government agency AFSSA, which regulates food products in a way similar to the United States FDA, granted approval of cranberry juice as an antibacterial agent for urinary tract health.[30]
To date, four completed randomized clinical trials have shown evidence for inhibiting bacterial infections in the urinary tract of women by drinking cranberry juice over a 12 month period.[31]
The US National Center for Complementary and Alternative Medicine (NCCAM) also reports three recently completed and four ongoing clinical trials of cranberry juice or capsules (pharmacy).[32] Six of these human studies are examining antibacterial effects in female urinary tract infections. One evaluates effects of cranberry polyphenols on cytochrome P450 enzymes involved in metabolism. To evaluate the drug interaction potential of cranberry, alprazolam, dextromethorphan and caffeine are being examined. As of January 2008, the results of these trials have not been published.
