Ginger — from the underground stem of the plant Zingiber officinale — has been widely used in traditional medicine for a variety of therapeutic purposes, one of which is relieving pain. Researchers in the UK conducted a systematic review to evaluate evidence from all clinical trials assessing the efficacy of ginger as a sole agent for the treatment of any pain condition. They conclude that, while some results seem promising, there is insufficient evidence to broadly recommend ginger for treating pain and inflammation.
Writing in the journal Pain Medicine online ahead of print, the researchers report searching multiple databases for controlled clinical trials examining oral ginger — capsule, tablet, extract, or powder — used as a sole agent compared with either an analgesic or placebo in adults suffering from any pain condition [Terry et al. 2011]. For their review, they discovered 7 articles published between 2000 and 2010, reporting a total of 8 trials (total N=481 participants).
Most group sizes were relatively small, ranging from 14 to 56 persons, and study periods ranged from 2 days to 24 weeks. The methodological quality and reporting of the studies was variable and a meta-analysis of data was not possible.
Of the 8 trials, 6 of them — 2 for osteoarthritis, 1 for dysmenorrhea, and 3 for experimentally induced acute muscle pain — found that ginger was efficacious in reducing subjective pain reports; affording either greater pain relief than placebo or relief comparable to active agents, such as ibuprofen. Adverse events, which were infrequent and mild, were reported in only a quarter of the trials.
Despite some promising benefits of ginger, particularly for osteoarthritis, the researchers conclude that evidence for its efficacy as a pain therapy remains insufficient, largely due to a paucity of well-conducted clinical trials.
COMMENTARY: It is disappointing, but not unexpected, that the research examining ginger as a pain reliever was so variable and of insufficient quality and quantity. This is a problem plaguing many areas of Complementary & Alternative Medicine (CAM), and basing recommendations on individual, short-term, underpowered trials could be inadvisable.
We had previously reported [here] on 2 of the studies included in this review by Terry et al., which found that that ginger capsules could help fend off muscle aches and pains after exercise; however, there were many shortcomings in this research. Furthermore, this present review excluded combination products of ginger with other ingredients, and we previously reported a study [here] of a ginger-feverfew mixture that was of some benefit for relieving mild migraine attacks. So, the possibility that ginger may provide more potent effects if used in combination with other herbal ingredients could merit further investigation.
Ginger is an interesting and complex mixture of pharmacological compounds, with several hundred constituents, and has been used as a medicine in Asian, Indian, and Arabic herbal traditions since ancient times. Among disorders other than pain, it has been used to treat stomach upset and nausea.
However, there are many questions about the optimal dose of ginger, the best formulation or quality of ingredients, and the duration of therapy needed to achieve the most beneficial outcomes. From the available research, these questions remain unanswered.
REFERENCE: Terry R, Posadzki P, Watson LK, Ernst E. The Use of Ginger (Zingiber officinale) for the Treatment of Pain: A Systematic Review of Clinical Trials. Pain Med. 2011(Nov 4); online ahead of print [abstract here].