Dietary ginger as a traditional therapy for blood sugar control in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND: Ancient medical practitioners used to encourage dietary supplements and herbal medicine for the treatment of type 2 diabetes mellitus (T2DM). Ginger (Zingiber officinale), is a nontoxic spice with negligible side effects, and is considered safe by the food and drug administration. In this analysis, we aimed to systematically compare fasting blood sugar (FBS) and glycated hemoglobin (HbA1c) at baseline versus at follow-up in T2DM patients who consumed and who did not consume ginger. METHODS: A literature search was carried out through MEDLINE, Embase, the Cochrane Central, and www.ClinicalTrials.gov for English-published trials comparing glucose parameters in T2DM patients who were assigned to ginger consumption versus a control group. All the participants were patients with T2DM who were either assigned to ginger therapy (1600– 4000 mg daily) or to a control group. FBS and HbA1c were assessed in the ginger and control groups, respectively, from baseline to follow-up to observe any significant change. Weight mean difference (WMD) with 95% confidence intervals (CI) was calculated to represent the analysis which was carried out by the RevMan 5.3 software. RESULTS: Eight randomized trials consisting of a total number of 454 participants with T2DM were included in this analysis. At first, FBS was compared in patients with T2DM from baseline prior to ginger consumption until follow-up after ginger consumption. The results showed no significant difference in FBS (WMD: 1.38, 95% CI: [−0.53–3.30]; P = .16). For the T2DM patients who did not consume ginger, no significant difference in FBS was observed (WMD: −0.27, 95% CI: [−5.09–4.54]; P = .91). However, a significantly improved HbA1c from baseline to follow-up was observed in those participants with ginger consumption (WMD: 0.46, 95% CI: [0.09–0.84]; P = .02) whereas in the control group, no significant difference in HbA1c was observed (WMD: −0.23, 95% CI: [−0.60–0.14]; P = .22). CONCLUSION: This analysis involving patients with T2DM showed no significant difference in FBS 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.