Ginger (Zingibe officinale) has long been among the range of dietary supplements and herbal medicines ancient medical practitioners used to recommend for the treatment of T2DM, thanks largely to its non-toxic nature, general safety, and negligible side effects.
Researchers at China's Youjiang Medical University for Nationalities conducted a systematic review and meta-analysis to compare fasting blood sugar and glycated haemoglobin (HbA1c) between T2DM patients who had consumed ginger and those who had not.
Treading gingerly
Using databases such as MEDLINE, Embase and the Cochrane Central, they selected eight English-language RCTs involving 454 patients, which compared glucose parameters in T2DM patients who had been administered ginger and a control group.
Those assigned to ginger therapy had each received a daily dose of between 1.6g to 4g of ginger, while those in the control groups had received an equivalent amount and frequency of placebo.
Patients in both groups had their fasting blood glucose and HbA1c assessed at baseline and during follow-up.
Initially, fasting blood glucose was compared in T2DM patients from baseline (prior to ginger consumption) to follow up (after ginger consumption). This showed no significant difference in fasting blood glucose — similar to T2DM patients who had not been administered ginger.
When it came to HbA1c, however, the researchers observed a "significantly improved" result between baseline and follow-up in the participants in the intervention group; a similarly significant result was not observed in the control group.
Past and present
The results differed somewhat from an earlier systematic review and meta-analysis, which reported that ginger consumption had managed to reduce fasting blood glucose and improve HbA1c in a significant manner.
However, the researchers wrote: "Their analysis was not strictly based on diabetic control and our analysis was better in the way that it included even more trials to assess the corresponding endpoints as compared to the previous meta-analysis."
They added that another study had found the daily consumption of 1g of ginger to be able to help reduce plasma fasting sugar, therefore preventing complications such as dyslipidaemia, hyper insulinaemia, peritoneal membrane fibrosis, and cardiovascular disease in patients undergoing peritoneal dialysis.
In addition to its anti-diabetic properties, previous research has also reported on ginger's effects against obesity and metabolic syndrome, as well as its protective effects on the liver, kidney, and neural system in T2DM patients.
Hypertensive patients and coronary artery disease patients may also benefit from dietary ginger consumption, which could even act as a "primary preventive measure" against chronic diseases.
Limitations and long-term prospects
The researchers acknowledged that the "restricted total number of participants could be a major limitation" of the current study, and that the variation in the length of the follow-up period for the different studies (eight to 12 weeks) could have affected the results.
At the same time, most of the studies did not report on the duration of T2DM in the participants, and the different amounts of ginger administered daily could have also been a limiting factor in the current study.
Lastly, none of the studies looked into any consumption of Western medicine by the patients, a factor that could have influenced the current study's final results.
In conclusion, the researchers wrote: "This analysis involving patients with T2DM showed no significant difference in fasting blood glucose with ginger consumption.
"However, dietary ginger significantly improved HbA1c from baseline to follow-up, showing that this natural medicine might have an impact on glucose control over a longer period of time in patients with T2DM."
Source: Medicine
http://dx.doi.org/10.1097/MD.0000000000015054
"Dietary ginger as a traditional therapy for blood sugar control in patients with type 2 diabetes mellitus: A systematic review and meta-analysis"
Authors: Fang-yan Huang, et al.