In the past, cinnamon’s glucose lowering effect has been studied in several randomized controlled trials (RCTs), but their results either lacked power due to the small sample sizes or results were just inconsistent. Allen et al, conducted a more recent meta-analysis of randomized controlled trials looking at cinnamon’s effect on patients with type 2 diabetes.
The RCTs included in the analysis studied the effects cinnamon had on diabetic patients vs. those who did not have diabetes (control group). Lab values were then obtained to measure these effects and either included: glycated hemoglobin (A1c), fasting plasma glucose, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), or triglyceride levels. Weighted mean differences among these levels were then calculated between the treatment group and control group.
Among the 10 RCTs included in the study, cinnamon doses ranged from 120 mg/d to 6 g/day for 4 to 18 weeks. It was found that the intake of cinnamon did decrease levels of fasting plasma glucose, total cholesterol, LDL-C, and triglyceride levels. It was also shown to increase levels of HDL-C, but it had no significant effect on A1c levels.
In conclusion, cinnamon’s antiglycemic effect in diabetic patients shows its consumption to be beneficial. However, since this meta-analysis does not focus on a standard dose of cinnamon to take among patients with diabetes, its clinical use is still limited.
Allen RW, et al. Cinnamon Use in Type 2 Diabetes: An Updated Systematic Review and Meta-Analysis. 2013; 11(5): 452-459.