Ginger (zingiber officinale) is a common part of the diet in many parts of the world. Recent research has found ginger to have various pharmacological properties due to a variety of active constituents, including shogaols and gingerols (responsible for the strong odor). Ginger is also one of the strongest plant antioxidants [1]. This article will provide a short summary of some of the advantages that supplementation with ginger or ginger extract may have to offer.

Benefits

Treatment of nausea – Ginger is probably most well-known for its ability to reduce nausea, and it has been superior to placebo in studies on seasickness, morning sickness, chemotherapy-induced nausea, motion sickness, pregnancy-related nausea, and others [2-5]. In the majority of these trials, the dosage used was 1 gram of ginger (either acutely or daily) and there were no adverse events. A few trials have not shown a statistically significant difference (although there has been at least one that has shown a significant difference for each of the conditions above), but there is always a trend toward improvement. Two possible mechanisms are enhanced intestinal transport and CNS activity, with studies in humans indicating that the latter is more likely [2].


Digestive stimulation – 6-shogaol, one of the active constituents in ginger, has stimulated intestinal blood flow and transport in rat and guinea pig studies [6, 7], indicating that it may effectively stimulate digestion. However, in a placebo-controlled trial ginger showed no effect on gastric emptying rate [8].


Cardiovascular health – Like other antioxidants, ginger may benefit cardiovascular health. A comprehensive study in mice found that ginger extract reduced cholesterol, inhibited LDL oxidation, and reduced the development of atherosclerosis [9]. A rat study found that ginger reduced plasma lipid levels, as well as lipid peroxidation [10]. No studies have yet been conducted on humans in this regard.


Cancer prevention – A few studies have been conducted on the effect ginger has on carcinogenesis. In vitro, ginger has selective anticancer activity [11]. A study in mice found that orally administered ginger significantly reduced the occurence of mammary tumors without adverse events as measured by body weight, food intake, and blood tests [12]. Ginger also improves immunologic function in mice that already have tumors [13].


Arthritis treatment – High doses of ginger may have anti-inflammatory [14] and analgesic [15] effects. One trial in patients with osteoarthritis found that ginger extract caused a modest reduction in knee pain [16].


Anxiety reduction – Animal models indicate that ginger may reduce anxiety through an unknown mechanism [17, 18]. The combination of ginkgo and ginger also facilitated learning in rats [17], but it is more than likely that this was due to the ginkgo.


Protection from pathogens – A comparison of 36 plant extracts found that ginger was among the strongest in inhibiting the growth of human pathogenic fungi, including strains that were resistant to traditional treatments [19]. Ginger has also shown activity against some respiratory tract pathogens [20]. The implication this has on humans in normal doses is not yet known.


Safety and use

Ginger has not been associated with any significant adverse events in trials. In some cases, gastrointestinal upset is reported. Doses as high as 1 g/kg have been used in rats with no signs of toxicity or teratogenicity [21]. .5-1 g per day is suggested for general health, 1 gram per day to prevent nausea, and 1 gram prior to travel for prevention of motion sickness.