Cinnamon for diabetes — a spice that lowers blood sugar?

Aim of the study: Although many randomized controlled trials (RCTs) have revealed the benefits of cinnamon for type 2 diabetes mellitus (T2DM), the effects of cinnamon supplementation on glycemic control in patients with T2DM are inconclusive. Therefore, the aim of this meta-analysis of RCTs was to assess the effects of cinnamon supplementation in managing glycemic control in patients with T2DM.

Results: Findings from 24 RCTs revealed that cinnamon supplementation significantly reduced fasting blood sugar (SMD: -1.32; 95% CI: -1.77, -0.87, p < 0.001), Homeostatic Model Assessment for Insulin Resistance (SMD: -1.32; 95% CI: -1.77, -0.87, p < 0.001), and hemoglobin A1C (SMD: -0.67; 95% CI: -1.18, -0.15, p = 0.011) compared with the control group in patients with T2DM. Additionally, cinnamon did not significantly change serum insulin levels (SMD: -0.17; 95% CI: -0.34, 0.01, p = 0.058). Our analysis indicated that cinnamon supplementation significantly lowers indicators of glycemic control. Together, these findings support the idea that cinnamon supplementation might have clinical potential as an adjunct therapy for managing T2DM.

Aim of the study: Cinnamon has been studied in randomized controlled trials (RCTs) for its glucose-lowering effects, but studies have been small and have shown conflicting results. A previous meta-analysis did not show significant results, but several RCTs have been published since then. We conducted an updated systematic review and meta-analysis of RCTs evaluating cinnamon’s effect on glucose and lipid levels.

Results: In a meta-analysis of 10 RCTs (n = 543 patients), cinnamon doses of 120 mg/d to 6 g/d for 4 to 18 weeks reduced levels of fasting plasma glucose (-24.59 mg/dL; 95% CI, -40.52 to -8.67 mg/dL), total cholesterol (-15.60 mg/dL; 95% CI, -29.76 to -1.44 mg/dL), LDL-C (-9.42 mg/dL; 95% CI, -17.21 to -1.63 mg/dL), and triglycerides (-29.59 mg/dL; 95% CI, -48.27 to -10.91 mg/dL). Cinnamon also increased HDL-C levels (1.66 mg/dL; 95% CI, 1.09 to 2.24 mg/dL). No significant effect on hemoglobin A1c levels (-0.16%; 95%, CI -0.39% to 0.02%) was observed. There was a high degree of heterogeneity in all analyses except HDL-C (I(2) ranging from 66.5% to 94.72%). Cinnamon consumption is associated with a statistically significant decrease in fasting plasma glucose, total cholesterol, LDL-C, and triglyceride levels, and an increase in HDL-C levels; however, no significant effect on hemoglobin A1c was found.

Aim of the study: Cinnamon, the dried bark and twigs of Cinnamomum spp., is a rich botanical source of polyphenols. It has been used for centuries in Chinese medicine and has been shown to affect blood glucose and insulin signaling.

Results: The eight clinical studies were identified through a literature search (Pub Med and Biosis through May 2010) for randomized, placebo-controlled trials reporting data on cinnamon and/or cinnamon extract and FBG. Comprehensive Meta-Analysis (Biostat Inc., Englewood, NJ, USA) was performed on the identified data for both cinnamon and cinnamon extract intake using a random-effects model that determined the standardized mean difference ([i.e., Change 1(control) - Change 2(cinnamon)] divided by the pooled SD of the post scores). Cinnamon intake, either as whole cinnamon or as cinnamon extract, resulted in a statistically significant reduction in FBG (-0.49±0.2 mmol/L; n=8, P=.025), and intake of cinnamon extract alone also lowered FBG (-0.48 mmol/L±0.17; n=5, P=.008). Thus, cinnamon extract and/or cinnamon improves FBG in people with type 2 diabetes or prediabetes.

Aim of the study: The objective of this study was to determine whether cinnamon improves blood glucose, triglyceride, total cholesterol, HDL cholesterol, and LDL cholesterol levels in people with type 2 diabetes.

Results: After 40 days, all three cinnamon doses reduced mean fasting serum glucose (18-29%), triglyceride (23-30%), LDL cholesterol (7-27%), and total cholesterol (12-26%) levels; no significant changes were observed in the placebo groups. Changes in HDL cholesterol were not significant. The results of this study show that taking 1, 3, or 6 g of cinnamon per day reduces serum glucose, triglyceride, LDL cholesterol, and total cholesterol in people with type 2 diabetes, and suggest that including cinnamon in the diet of people with type 2 diabetes will reduce risk factors associated with diabetes and cardiovascular disease.

Aim of the study: Previous clinical studies showing that cinnamon spice lowers blood glucose concentrations have had inconsistent results. This study aimed to determine the effect of daily cinnamon spice supplementation, in an amount commonly used as a seasoning, on glucose concentrations in adults with obesity and prediabetes.

Results: There were 694 follow-up days with 66,624 glucose observations. Compared with placebo, 24-hour glucose concentrations were significantly lower when cinnamon was given [mixed-models; effect size (ES) = 0.96; 95 % confidence interval (CI): -2.9, -1.5; P < 0.001]. Similarly, the mean net area under the curve (netAUC) for glucose was significantly lower than with placebo when cinnamon was given (over 24 h; ES = -0.66; 95 % CI: 2501.7, 5412.1, P = 0.01). Cinnamon supplementation resulted in lower glucose peaks compared with placebo (Δpeak 9.56 ± 9.1 mg/dL compared with 11.73 ± 8.0 mg/dL; ES = -0.57; 95 % CI: 0.8, 3.7, P = 0.027). Glucose-dependent insulinotropic polypeptide concentrations increased during oral glucose tolerance testing plus cinnamon testing (mixed-models; ES = 0.51; 95 % CI: 1.56, 100.1, P = 0.04), whereas triglyceride concentrations decreased (mixed-models; ES = 0.55; 95 % CI: -16.0, -1.6, P = 0.02).

Aim of the study: The search for new antihyperglycemic agents from herbal medicines has highlighted cinnamon, which contains biologically active compounds with insulin-mimicking effects in vitro. We assessed the efficacy and safety of Cinnamomum zeylanicum (CZ) extract in people with Type 2 Diabetes.

Results: The mean age of participants was 58.6 ± 8.2 years, and 42.9 % (n = 90) were male; 186 completed the four-month follow-up. Both FPG and HbA1c declined significantly in the CZ extract groups compared with baseline, alongside reduced insulin resistance and improved β-cell function (p < 0.05). At four months, total and LDL cholesterol were significantly lower in the 500 mg CZ extract group (p < 0.05). Regression analyses identified CZ extract treatment as a significant predictor of changes in both FPG and HbA1c. This randomized controlled trial developed and tested a CZ-based intervention for Type 2 Diabetes, demonstrating promising efficacy and safety. Further studies are warranted to explore its potential as a pharmaceutical agent for diabetes management.

Aim of the study: Multiple studies have evaluated the blood-glucose-lowering effect of cinnamon in patients with type II diabetes mellitus (DM), with conflicting results. Differences in patients’ baseline Body Mass Index (BMI) may explain the observed differences in results. This study was designed to evaluate the effect of cinnamon supplementation on anthropometric, glycemic, and lipid outcomes in patients with type II DM based on their baseline BMI.

Results: Cinnamon supplementation led to improvements in all anthropometric (BMI, body fat, and visceral fat), glycemic (FPG, 2hpp, HbA1C, fasting insulin, and insulin resistance), and lipid (total cholesterol, LDL-c, and HDL-c) outcomes, except triglyceride levels. All observed changes, except for total cholesterol and LDL-c, were significantly greater in patients with a higher baseline BMI (BMI ≥ 27). Based on the study findings, cinnamon may improve anthropometric parameters, glycemic indices, and lipid profiles in patients with type II diabetes. These benefits are significantly greater in patients with a higher baseline BMI (BMI ≥ 27). The trial protocol was registered in the Iranian Registry of Clinical Trials database (registration ID: IRCT2017031133015N1).

Aim of the study: Aim: We examined the possible impact of cinnamon on blood glucose and some biochemical parameters among type 2 diabetic patients treated with cinnamon in Najaf.

Results: Results: Our study supports previous findings on the beneficial effect of cinnamon in lowering blood glucose levels in people with diabetes. However, our study highlighted several points. First, it is more effective at lowering fasting blood glucose than random blood glucose. Second, soaked parts are more effective than boiled parts. In addition, the only urine biochemical parameters affected by cinnamon (reduced urine concentration) were urine glucose and urine ketones; there was no effect on urine pH, specific gravity, or total proteins. Further studies are required to extend the treatment period, test a range of cinnamon concentrations, and use a double-blind study with a placebo. Conclusions: Fasting blood glucose, urine glucose, and urine ketones were reduced by treatment with cinnamon, with soaking more effective than boiling and branches more effective than powder.

Aim of the study: Cinnamon has a long history as an antidiabetic spice, but trials involving cinnamon supplementation have produced conflicting results. The aim of this review was to examine the results of randomized controlled clinical trials of cinnamon and evaluate its therapeutic potential in patients with diabetes and insulin resistance, particularly its ability to reduce blood glucose levels and inhibit protein glycation.

Results: Five studies in people with type 2 diabetes and three in people without diabetes (total N = 311) were eligible. Two of the diabetic studies showed significant fasting blood glucose (FBG) reductions of 18-29% and 10.3% (p < 0.05), supported by one trial in people without diabetes reporting an 8.4% FBG reduction (p < 0.01) versus placebo, and another showing significant reductions in glucose response using oral glucose tolerance tests (p < 0.05). Three diabetic studies reported no significant results. Although definitive conclusions cannot be drawn about the use of cinnamon as an antidiabetic therapy, it does have antihyperglycemic properties and the potential to reduce post-meal blood glucose levels. Further research is needed to confirm a possible relationship between baseline FBG and blood glucose reduction and to assess cinnamon supplementation’s potential to reduce diabetes-related complications.

Aim of the study: Cinnamon (Cinnamomum spp.) has long been used as a culinary spice. Its bioactive constituents, principally cinnamaldehyde (55-85% of bark oil), Type-A procyanidins, and phenolic acids, have attracted increasing attention for their role in glycemic regulation.

Results: Safety remains important, as cassia varieties may contain up to 3.6 g/kg coumarin compared with ≤15 mg/kg in C. verum, with implications for intake relative to the EFSA tolerable daily intake. Unlike reviews focused primarily on pharmacological effects, this work takes a food-matrix-oriented perspective. It introduces a three-step framework—species selection, matrix matching, and authentication—to guide evidence-based functional food development, while identifying species-authenticated bioavailability trials and food-based RCTs as research priorities.