The effect of ginger supplementation on serum C-reactive protein, lipid profile and glycaemia: a systematic review and meta-analysis.
OBJECTIVE
To undertake a systematic review and meta-analysis of prospective studies to determine the effect of ginger supplementation on serum C-reactive protein (CRP), lipid profile, and glycaemia.


METHODS
PubMed-MEDLINE, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until July 2016) to identify prospective studies evaluating the impact of ginger supplementation on serum CRP. Random-effects model meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using theI2index. Systematic review registration: CRD42016035973.


RESULTS
From a total of 265 entries identified via searches, 9 studies were included in the final selection. The meta-analysis indicated a significant reduction in serum CRP concentrations following ginger supplementation [weighted mean difference (WMD)-0.84 mg/L (95% CI -1.38 to -0.31,I256.3%)]. The WMD for fasting blood glucose and HbA1c was -1.35 mg/dl (95% CI -2.04 to -0.58,I212.1%) and -1.01 (95% CI -1.28 to -0.72,I29.4%), respectively. Moreover, high-density lipoprotein and triglyceride significantly improved after ginger administration [1.16 mg/dl (95% CI 0.52 to 1.08,I212.3%) and -1.63 mg/dl (95% CI -3.10 to -0.17,I28.1%), respectively]. These findings were robust in sensitivity analyses. Random-effects meta-regression revealed that changes in serum CRP levels were independent of the dosage of ginger supplementation (slope -0.20; 95% CI -0.95 to 0.55;p=0.60).


CONCLUSIONS
This meta-analysis suggests that ginger supplementation significantly reduces serum CRP and improves glycaemia indexes and lipid profile. Randomized control trials with larger sample size and with a longer-term follow-up period should be considered for future investigations.
Key State Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.|Institute of Genetics and Developmental Biology, International College, University of Chinese Academy of Science, Beijing, China.
Mohsen
M
Mazidi
Department of General Surgery, The General Hospital of Chinese People's Armed Police Forces, Beijing, China; gao.hongkai@mayo.edu.
Hong-Kai
HK
Gao
Biochemistry of Nutrition Research Center, School of Medicine, Mashhad University of Medical Science, Mashhad, Iran.
Peyman
P
Rezaie
Division of Medical Education, Brighton and Sussex Medical School, University of Brighton, Brighton, United Kingdom.
Gordon A
GA
Ferns
C-reactive protein; fasting blood glucose; ginger; lipids; meta-analysis; supplementation