Akilen R, Tsiami A, Devendra D, Robinson N. Cinnamon in glycaemic control: Systematic review and meta analysis. Clin Nutr. 2012;31(5):609-615.
A systematic review and meta-analysis examining the effect of cinnamon on glycemic control in patients with type-2 diabetes mellitus.
A systematic literature search was conducted up to August 1, 2011, seeking published clinical trials on humans using cinnamon and looking at impact on type 2 diabetes. A total of 6 clinical trials met the inclusion criteria.
Study Medication and Dosage
Data from a total of 435 patients was included in the analysis. The patients were followed for between 40 days and 4 months. Cinnamon doses ranged from 1 to 6 grams per day.
Changes in hemoglobin A1c and fasting plasma glucose (FPG) were calculated.
Meta-analysis of the data showed a significant decrease in mean HbA1c [0.09%; 95% CI: 0.04–0.14] and mean FPG [0.84 mmol/l; 95% CI: 0.66–1.02].
There is a certain allure to the idea that diabetes can be controlled with cinnamon that is hard to explain. Is it that type 2 diabetics possess an above average appreciation for foods containing cinnamon? Whatever the explanation, the trend to use cinnamon to control blood sugar has become popular with the public and we are seeing patients who expect to successfully treat their blood sugar problems with cinnamon. The actual results may not meet their expectations.
We should pay close attention to this paper by Akilen et al as it quantifies the potential benefit cinnamon could provide. This is not the first meta-analysis on the subject. An earlier paper by Davis and Yokoyama published in the September 2011 issue of the Journal of Medicinal Food selected 8 clinical trials and also found a significant improvement in fasting blood glucose (FBG). They reported, “Cinnamon intake, either as whole cinnamon or as cinnamon extract, results in a statistically significant lowering in FBG.”1
As Steve Austin, ND, has taught us, we need to apply a basic question to these research findings: Are these results just statistically significant or will they also be clinically significant?
To do answer this question, we first need to translate all these numbers into familiar units. Akilen reported a 0.09% decrease in hemoglobin A1c. If a patient lowered her A1c to 8.00% from 8.09% (the decrease reported by Akilen) that would mean the patient’s 3-month average blood sugar had dropped from 183 to 180 mg/dL. Fasting blood sugars dropped by 0.84 mmol/l, equivalent to a 15.1 mg/dL drop.
Davis’ study reported a FBG drop of 0.82 mmol/L, or 14.8 mg/dL—almost the same as Akilen.
How do these improvements compare to other treatments for type-2 diabetes?
A February 2012 meta-analysis on the effect of metformin, combining data from 35 clinical trials, reported that using metformin alone lowered A1c by 1.12% compared to placebo—more than a dozen times the effect of cinnamon reported by Akilen.2
Nilsen et al reported in a Norwegian trial of exercise and diet that those participants who lost more than 5% of their body weight and improved their aerobic capacity 1 or more Metabolic Equivalent of Task reduced their A1c from 5.8 to 5.5%. Only 24 out of 182 study participants met these 2 goals.3
Though it’s a challenge to lose weight and improve fitness, this 0.3% decrease in A1c is more than triple the effect seen with cinnamon.
Our patients who think that sprinkling cinnamon on their toast will fix their diabetes are barking up the wrong tree.
In 2008 Yin et al reported that in a pilot study using berberine in type-2 diabetics (500 mg 3 times/day for 3 months), A1c averages dropped from 9.5% to 7.5%. That’s 22 times the reported effect of cinnamon.
Normalizing vitamin D and supplementing with calcium lowered A1c by 0.7% in a group of Asian type-2 diabetics, according to a 2010 Report by Sabherwal et al. That is nearly 8 times the change seen from cinnamon.
The bottom line is that although Akilen’s new study provides the statistical strength to tell us that cinnamon does have an effect, the effect turns out to be modest and is surpassed by other supplements, as well as lifestyle and pharmaceutical interventions. Our patients who think that sprinkling cinnamon on their toast will fix their diabetes are barking up the wrong tree.
- Davis PA, Yokoyama W. Cinnamon intake lowers fasting blood glucose: meta-analysis. J Med Food. 2011;14(9):884-889.
- Hirst JA, Farmer AJ, Ali R, Roberts NW, Stevens RJ. Quantifying the effect of metformin treatment and dose on glycemic control. Diabetes Care. 2012;35(2):446-454.
- Nilsen V, Bakke PS, Gallefoss F. Effects of lifestyle intervention in persons at risk for type 2 diabetes mellitus—results from a randomised, controlled trial. BMC Public Health. 2011;11:893.