Garlic intake lowers fasting blood glucose: meta-analysis of randomized controlled trials

Asia Pac J Clin Nutr. 2015;24(4):575-82. doi: 10.6133/apjcn.2015.24.4.15.


Garlic is a common spicy flavouring agent also used for certain therapeutic purposes. Garlic's effects on blood glucose have been the subject of many clinical and animal studies, however, studies reporting hypoglycemic effects of garlic in humans are conflicting. A comprehensive literature search was conducted to identify relevant trials of garlic or garlic extracts on markers of glycemic control [fasting blood glucose (FBG), postprandial glucose (PPG), glycosylated haemoglobin (HbA1c)]. A meta-analysis of the effect of garlic intake on human was done to assess garlic's effectiveness in lowering glucose levels. Two reviewers extracted data from each of the identified studies. Seven eligible randomized controlled trials with 513 subjects were identified. Pooled analyses showed that garlic intake results in a statistically significant lowering in FBG [SMD=-1.67; 95% CI (-2.80, -0.55), p=0.004]. Our pooled analyses did not include PPG control and HbA1c outcomes. Because only 1 study included in the meta-analysis reported PPG variables and only 2 studies reported HbA1c variables. In conclusion, the current meta-analysis showed that the administration of garlic resulted in a significant reduction in FBG concentrations. More trials are needed to investigate the effectiveness of garlic on HbA1c and PPG.

大蒜是一种常见的辛辣调味剂,也可用于某些疾病的治疗。目前已有关于大蒜 对血糖影响的临床和动物研究。但各研究结论存在争议。本研究通过meta分析 探讨大蒜对人体血糖的影响。全面检索相关数据库,对符合纳入标准的随机对 照研究,由两位评审员按Cochrane系统评价方法独立进行资料提取、质量评价 并交叉核对后进行meta分析。共纳入7篇随机对照试验文章,合计513人。Meta 分析结果显示:与安慰剂对照组相比,大蒜摄入组空腹血糖水平显著降低 [SMD=-1.67;95% CI (-2.80,-0.55),p=0.004]。由于纳入的研究中仅有1个 研究提供了餐后血糖相关数据,2个研究提供糖化血红蛋白相关数据,故本研 究未对餐后血糖和糖化血红蛋白进行meta分析。总之,本研究结果提示大蒜摄 入可以降低空腹血糖水平。仍需更多研究探讨大蒜对糖化血红蛋白及餐后血糖 的影响。.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Blood Glucose / analysis*
  • Diet*
  • Fasting
  • Garlic* / chemistry
  • Glycated Hemoglobin A / analysis
  • Humans
  • Hypoglycemic Agents
  • Postprandial Period
  • Randomized Controlled Trials as Topic*


  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents