Bottom Line: Ginger is effective in preventing nausea and vomiting in some people. However, patients taking blood thinners or about to undergo surgery should avoid ginger supplements.
Ginger root contains compounds that may help to relieve or prevent nausea and vomiting. These substances stimulate the flow of saliva and the secretion of digestive juices. They can also calm the contractions of the stomach and intestine. Scientists are still unsure exactly how ginger exerts these effects. In humans, studies have shown that eating fresh ginger (but not dried ginger) in high doses can "thin" the blood by preventing platelet aggregation. In addition, one laboratory study suggested that ginger can protect brain cells from the plaques that cause Alzheimer's disease, but this effect has not been replicated in humans.
To stimulate the appetite Ginger is known to stimulate the flow of saliva and digestive secretions, but no clinical trials have been performed to test this use.
To treat colic and reduce gas in the stomach and intestine Compounds found in ginger are known to calm the contractions of the stomach and intestine, but no clinical trials have been performed to test this use.
To treat diarrhea Compounds found in ginger are known to calm the contractions of the stomach and intestine, but no clinical trials have been performed to test this use.
To relieve symptoms of drug withdrawal Clinical trials show that ginger can relieve nausea, but no scientific evidence supports its use for any other symptoms of drug withdrawal.
To relieve indigestion Ginger is known to stimulate the flow of saliva and digestive secretions, but no clinical trials have been performed to evaluate this use.
To treat nausea and vomiting Several clinical trials support the use of ginger for short-term treatment of nausea and vomiting associated with pregnancy, motion sickness, and surgical anesthesia.
To treat rheumatoid arthritis and osteoarthritis The few clinical trials that studied this use have shown some, although not very strong, support.
Nausea and vomiting during pregnancy: To test the ability of ginger to treat pregnancy-related nausea and vomiting, researchers randomly gave 70 women early in their pregnancy (less than 17 weeks along) either one gram of ginger or a placebo. All of the patients had episodes of vomiting 24 hours prior to starting the study. After four days of therapy with ginger or a placebo, women taking ginger reported significantly fewer episodes of nausea and vomiting than women taking the placebo. In addition, women taking ginger had no more problems with their pregnancies than women taking the placebo, suggesting that ginger is safe of pregnant women to take.
Another trial of ginger involved 291 women less than 16 weeks pregnant. The women were randomly assigned to receive either ginger or vitamin B6 (a vitamin that is known to reduce nausea and vomitind during pregancy) daily for three weeks. Women receiving ginger had similar reduction in nausea, retching and vomiting.
Post-surgery nausea and vomiting: Many patients experience nausea and vomiting after general anesthesia for surgery. A randomized, controlled trial compared ginger root to a placebo pill and to metoclopramide, a prescription anti-vomiting drug, to prevent post-operative nausea and vomiting. One hundred and twenty women who were undergoing laparoscopic outpatient surgery enrolled in the study. After surgery, ginger performed as well as metoclopramide in preventing nausea and vomiting, and both did better than the placebo pill.
In a similar study, 60 women who were undergoing major gynecological surgery took ginger root, metoclopramide, or a placebo pill to test their effects on post-surgical nausea and vomiting. As in the last study, ginger performed as well as metoclopramide, and both fared better than the placebo pill at preventing nausea and vomiting.
Due to its blood thinning effects, you may want to stop taking ginger supplements a week or two before undergoing surgery. Consult with your surgeon about any supplements you are taking.
This product is regulated by the FDA as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. The product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness.
Derived from the root and rhizome of the plant, ginger has been used as food and as medicine primarily for gastrointestinal symptoms. Clinical studies suggest that ginger reduces nausea and vomiting post-operatively (2), during pregnancy (3)(4), after chemotherapy (5) and associated with motion sickness (6). Ginger also influences gastric emptying in healthy individuals (7). Results from in vitro studies indicate that ginger inhibits growth of gastric (8), colorectal (9), and ovarian cancer (10) cells,but these effects have not been shown in humans. Another in vitro study suggests ginger may have protective effects against Alzheimer's disease (11). Possible adverse effects include heartburn and dermatitis (12). Consumption of excessive amounts may result in CNS depression and arrhythmias. Because ginger can inhibit thromboxane formation and platelet aggregation, concomitant use with anticoagulants may increase the risk of bleeding (13)(14)(15). Other potential drug interactions include an increased effect of hypoglycemics and anti-hypertensive agents, and decreased efficacy of histamine-2 blockers (e.g. ranitidine) and proton-pump inhibitors (e.g. lansoprazole) (13).
The antiemetic action of ginger is attributed to the shogaol and gingerol constituents found in the rhizome. They are believed to stimulate the flow of saliva, bile, and gastric secretions. Additional activities include the suppression of gastric contractions and improvement of the intestinal muscle tone and peristalsis (17). Galanolactone is thought to interact with 5HT-3 receptors and may be partially responsible for the antiemetic activity (18). Ginger has been shown to inhibit thromboxane formation and inhibit platelet aggregation (15); however, this effect appears dependent on dose and formulation (e.g., dried, fresh, or extract) (19). An in vitro study suggests that ginger may have therapeutic effects against Alzheimer's disease by protecting neuronal cells from beta-amyloid insult (11). Apoptosis of gastric cancer cells by gingerol is mediated through TRAIL-dependent caspase 3/7 activation while shogaol alone reduces in vivo tumor growth (8). In colorectal cancer cells, gingerol inhibits cell cycle progression by reducing cyclin D1 expression and induces apopotsis (9), while in ovarian cancer cells, ginger inhibits secretion of angiogenic cytokines such as VEGF and IL-8 (10).
Anticoagulants / Antiplatelets: Ginger may increase the risk of bleeding. H2-blockers / Proton pump inhibitors: Ginger may antagonize activity by increasing stomach acid production. Antihypertensives: Ginger may cause additive hypotensive effects. Hypoglycemics / Insulin: Ginger may cause additive reductions in blood glucose. (7)
Wu KL, et al. Effects of ginger on gastric emptying and motility in healthy humans. Eur J Gastroenterol Hepatol 2008;20(5):436-440. The influence of ginger on gastric emptying and motility was assessed in this randomized, double-blind, controlled study of 24 healthy participants. Following an 8 hour fast, participants received placebo or 1200 mg of ginger. After 1 hour, participants consumed a low-nutrient soup (500 ml) after which dimensions of the antrum and fundus and antral contractions were analyzed. In participants that received ginger, antral area was reduced and contractions were more frequent. The authors suggest using more sensitive three-dimensional ultrasound or MRI to further define the exact stomach areas affected by ginger. Because this study analyzed healthy individuals, the effect of ginger on gastric emptying and motility should also be assessed in individuals with gastrointestinal symptoms such as dyspepsia.
Vutyavanich T, Kraisarin T, Ruangsri R. Ginger for nausea and vomiting in pregnancy: randomized, double-masked, placebo-controlled trial. Obstet Gynecol 2001;97:577-82. Administration of ginger to women less than 17 weeks pregnant and experiencing related nausea and vomiting were included in this study. Seventy women (32 ginger, 38 placebo) were enrolled and administered the study medication four times a day for 4 days. All patients had episodes of vomiting 24 hours prior to enrollment. Nausea and vomiting scores were significantly reduced on the fourth day of treatment with ginger as compared to placebo. On day 4, 12 of 32 patients receiving ginger compared to 23 of 35 on placebo had at least one episode of vomiting. No difference in outcome of pregnancy was noted between the groups. This study suggests that ginger is effective for short term management of nausea and vomiting associated with pregnancy.
Smith C, Crowther C, Willson K, Hotham N, McMillian V. A randomized controlled trial of ginger to treat nausea and vomiting in pregnancy. Obstet Gynecol. 2004 Apr;103(4):639-45. 291 women less than 16 weeks pregnant participated in this study of ginger and the nausea and vomiting due to pregnancy. The women were randomly assigned to receive either 1.05 grams of ginger or 75 mg of Vitamin B6 daily for three weeks. Nausea and vomiting scores were measured weekly. Women receiving ginger had similar reductions in nausea, vomiting and retching as those receiving vitamin B6. In addition, women in both groups had similar outcomes of pregnancy suggesting that ginger is a safe and effective treatment for nausea and vomiting due to pregnancy.
