Ginger is an herb that is used as a spice and also for its therapeutic qualities. The underground stem (rhizome) can be used fresh, powdered, dried, or as an oil or juice. Ginger is part of the Zingiberaceae family, as are cardamom, turmeric and galangal.
According to the National Library of Medicine, part of the NIH (National Institutes of Health), ginger is widely used throughout the world for treating loss of appetite, nausea and vomiting after surgery, nausea resulting from cancer treatment, flatulence, stomach upset, colic, morning sickness and motion sickness.
In some parts of the world, ginger juice is applied to the skin to treat burns.
Ginger is also used as a flavoring by the food and drinks industry, as a spice and flavoring in cooking, and for fragrance in soaps and cosmetics.
Ginger contains a chemical that is used as an ingredient in antacid, laxative and anti-gas medications.
According to Kew Gardens, England's horticultural royal center of excellence, ginger has a long history of usage in South Asia, both in fresh and dried form.
The Mahabharata (circa 4th century BC), one of the two major Sanskrit epics of ancient India, describes a stewed meat meal which includes ginger. Ginger has also been a key plant in Ayurvedic medicine, a system of traditional medicine native to the Indian subcontinent.
Approximately 2000 years ago, ginger was exported from India to the Roman empire, where it became valued for its therapeutic as well as culinary properties.
Ginger continued to be traded in Europe after the fall of the Roman empire, where its supply was controlled by Arab traders for hundreds of years. During medieval times it became a popular ingredient in sweets.
During the 13th and 14th centuries ginger and black pepper were commonly traded spices. By the sixteenth century one pound in weight of ginger in England would cost the equivalent of one sheep.
What are the therapeutic benefits of ginger?
Below are examples of some scientific studies on ginger and its current or potential uses in medical treatment.
Inflammation of the colon
A study carried out at the University of Michigan Medical School found that Ginger Root Supplement administered to volunteer participants reduced inflammation markers in the colon within a month.
The study was published in the journal Cancer Prevention Research.
Experts say that inflammation of the colon is a precursor to colon cancer. Co-researcher Suzanna M. Zick, N.D., M.P.H., explained that by reducing inflammation in the colon a person reduces their risk of developing colon cancer.
Zick said "We need to apply the same rigor to the sorts of questions about the effect of ginger root that we apply to other clinical trial research. Interest in this is only going to increase as people look for ways to prevent cancer that are nontoxic, and improve their quality of life in a cost-effective way."
Muscle pain caused by exercise
A study involving 74 volunteers carried out at the University of Georgia found that daily ginger supplementation reduced exercise-induced muscle pain by 25%.
Patrick O'Connor, a professor in the College of Education's department of kinesiology, and colleagues carried out two studies on the effects of 11 days of raw and heat-treated ginger supplementation on exercise-induced muscle pain.
The volunteers consumed the ginger supplements for 11 consecutive days. On the 8th day they performed 18 extensions of the elbow flexors with a heavy weight. The aim was to induce moderate muscle injury to the arm. Each participant's arm function, inflammation, and pain levels were assessed before exercise and three days afterwards.
The researchers noted that the pain-reducing effect was not enhanced by heat-treating the ginger.
The study was published in The Journal of Pain.
Nausea caused by chemotherapy
Ginger supplements administered alongside anti-vomiting medications can reduce chemotherapy-induced nausea symptoms by 40%, a PhaseII/III study carried out at the University of Rochester Medical Center found.
Lead researcher, Dr Julie Ryan, presented the study findings at the American Society of Clinical Oncology meeting in Orlando, Florida, in 2009.
Dr. Ryan explained that about 70% of cancer patients who receive chemotherapy experience nausea and vomiting. The vomiting is usually easy to control with effective medications. However, the nausea tends to linger.
Dr. Ryan said "By taking the ginger prior to chemotherapy treatment, the National Cancer Institute-funded study suggests its earlier absorption into the body may have anti-inflammatory properties."
A study found that exposing ovarian cancer cells to a solution of ginger powder resulted in their death in every single test.
The cancer cells either died as a result of apoptosis (they committed suicide) or autophagy (they digested/attacked themselves).
The researchers, from the University of Michigan Comprehensive Cancer Center added that the ginger solution also prevented the cancer cells from building up resistance to cancer treatment.
The study findings were presented at the American Association for Cancer Research annual meeting in Washington D.C., 2006.
A team at Columbia University carried out a study to determine what effects adding specific components of ginger to asthma medications might have on asthma symptoms.
Team leader, Elizabeth Townsend, PhD, explained "In our study, we demonstrated that purified components of ginger can work synergistically with β-agonists to relax ASM (airway smooth muscle)."
The scientists took ASM tissue samples and exposed them to acetylcholine, a compound that causes bronchoconstriction (narrowing of the airways).
They then mixed the β-agonist isoproterenol (asthma medication) with three different components of ginger:
Contracted ASM tissue samples were exposed to each of the three mixtures as well as isoproterenol on its own.
The team found that ASM tissues exposed to isoproterenol combined with the purified ginger components exhibited greater relaxation than those treated with just isoproterenol.
Ginger component 6-shogaol had the greatest impact in enhancing the effects of isoproterenol.
Dr. Townsend said "Taken together, these data show that ginger constituents 6-gingerol, 8-gingerol and 6-shogaol act synergistically with the β-agonist in relaxing ASM, indicating that these compounds may provide additional relief of asthma symptoms when used in combination with β-agonists. By understanding the mechanisms by which these ginger compounds affect the airway, we can explore the use of these therapeutics in alleviating asthma symptoms."
The study findings were presented at the American Thoracic Society International Conference 2013 in Philadelphia, Pennsylvania.
Liver damage caused by acetaminophen
Acetaminophen, known more commonly as "Tylenol" in the USA and "paracetamol" elsewhere, is a popular painkiller and antipyretic (reduces fever). However, acetaminophen is also associated with a higher risk of chemically-driven liver damage (hepatotoxicity), especially among patients with liver disorders.
Scientists at the National Research Centre in Egypt wanted to determine whether ginger pretreatment might reduce the incidence of acetaminophen-induced liver damage in rats.
The researchers wrote in the Journal of Dietary Supplements "Our results demonstrated that ginger can prevent hepatic injuries, alleviating oxidative stress in a manner comparable to that of vitamin E. Combination therapy of ginger and acetaminophen is recommended especially in cases with hepatic (liver) disorders or when high doses of acetaminophen are required."
High blood pressure (hypertension)
A study reported in the journal Pharmaceutical Biology found that cassumunar ginger extract was more effective than prazosin hydrochloride in reducing blood pressure in hypertensive laboratory rats.
The researchers, from Chiang Mai University in Thailand wrote "The cassumunar ginger extract exhibited the maximum decrease of mean arterial blood pressure at 39.83 ± 3.92%, which was 3.54-times that of prazosin hydrochloride."
Dysmenorrhea (painful menstruation)
Seventy female students were divided into two groups:
- The ginger group - they took capsules containing ginger
- The placebo group - participants took capsules containing placebo
The participants took their capsules for three days at the beginning of their menstruation cycles.
The researchers found that the 82.85% of the women taking the ginger capsules reported improvements in pain symptoms compared to 47.05% of those on placebo.
A study performed at the VALI-e-ASR Hospital in Iran and published in the journal Phytotherapy Research found that ginger powder is as effective in treating common migraine symptoms as sumatriptan. Sumatriptan is a common medication for migraine treatment (Imitrex, Treximet, Imigran, Imigran).
The double-blind, randomized clinical trial involved 100 participants. They all suffered form acute migraine without aura. They were randomly selected to receive either sumatriptan or ginger powder.
The study authors concluded "Efficacy of ginger powder and sumatriptan were similar. Clinical adverse effects of ginger powder were less than sumatriptan. Patients' satisfaction and willingness to continue did not differ. The effectiveness of ginger powder in the treatment of common migraine attacks is statistically comparable to sumatriptan. Ginger also poses a better side effect profile than sumatriptan."
Written by Christian Nordqvist