Cinnamon: Research
Overview
This page provides a curated overview of selected peer-reviewed scientific studies examining cinnamon, a spice derived from the bark of trees within the Cinnamomum genus. The goal of this page is to provide transparent access to commonly cited research in the scientific literature. The summaries below describe findings reported in published studies. They are presented for educational purposes as part of a clinician-led review of the scientific literature.
Important Context for Readers
Scientific studies examine outcomes in defined populations under specific research conditions. Results reported in individual studies may not apply to all individuals, and findings should not be interpreted as guaranteed outcomes. This page summarizes selected research examining metabolic biomarkers and biological mechanisms studied in relation to cinnamon. It is not intended to provide medical advice, diagnosis, or treatment recommendations. This page is provided for educational purposes and does not include product recommendations or affiliate links.
Summary of Evidence
Across human clinical studies and meta-analyses, cinnamon supplementation has been studied for its potential associations with changes in selected metabolic biomarkers, including fasting glucose, HbA1c, insulin resistance markers, lipid parameters, blood pressure, and body composition.
While results vary across study populations and trial designs, several randomized studies and meta-analyses have reported modest changes in glucose-related and lipid-related biomarkers under study conditions. The studies listed below represent frequently cited papers within the cinnamon literature. Many studies involve small sample sizes, short durations, different cinnamon species or extracts, and selected study populations, which may limit generalizability.
Key Areas of Research
Metabolic Support
Evidence strength: Moderate.
Randomized trials and meta-analyses have examined the relationship between cinnamon and biomarkers related to glucose metabolism, including fasting glucose, HbA1c, insulin, and insulin resistance markers.
1) Khan A, Safdar M, Ali Khan MM, et al. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care. 2003.
PMID: 14633804
DOI: https://doi.org/10.2337/diacare.26.12.3215
Population: Adults with type 2 diabetes.
Design: Randomized controlled study evaluating 1 g, 3 g, or 6 g of cinnamon daily for 40 days, followed by a washout period.
Key findings:
• Fasting serum glucose reductions of approximately 18–29% were reported in the studied population
• Triglycerides decreased approximately 23–30%
• LDL cholesterol decreased approximately 7–27%
• Total cholesterol decreased approximately 12–26%
• HDL cholesterol did not significantly change
• Findings contributed substantially to subsequent clinical research evaluating cinnamon and metabolic biomarkers.
2) Mang B, Wolters M, Schmitt B, et al. Effects of a cinnamon extract on plasma glucose, HbA1c, and serum lipids in diabetes mellitus type 2. European Journal of Clinical Investigation. 2006.
PMID: 16634838
DOI: https://doi.org/10.1111/j.1365-2362.2006.01629.x
Population: Adults with type 2 diabetes.
Design: Randomized, placebo-controlled trial evaluating a cinnamon extract over 4 months.
Key findings:
• Fasting plasma glucose decreased in the cinnamon extract group
• HbA1c and serum lipid changes were less consistent
• The study suggested that cinnamon extract may influence glucose biomarkers in selected study populations
• Results also highlighted variability between cinnamon preparations and clinical outcomes
3) Vanschoonbeek K, Thomassen BJW, Senden JM, et al. Cinnamon supplementation does not improve glycemic control in postmenopausal type 2 diabetes patients. Journal of Nutrition. 2006.
PMID: 16549460
DOI: https://doi.org/10.1093/jn/136.4.977
Population: Postmenopausal adults with type 2 diabetes.
Design: Randomized controlled trial evaluating 1.5 g/day of Cinnamomum cassia for 6 weeks.
Key findings:
• Cinnamon supplementation did not significantly improve fasting plasma glucose
• Insulin concentrations and insulin sensitivity measures did not significantly improve
• Lipid biomarkers did not significantly change
• This study is important because it illustrates the inconsistent findings across cinnamon trials
4) Blevins SM, Leyva MJ, Brown J, et al. Effect of cinnamon on glucose and lipid levels in non-insulin-dependent type 2 diabetes. Diabetes Care. 2007.
PMID: 17563345
DOI: https://doi.org/10.2337/dc07-0098
Population: Adults with non-insulin-dependent type 2 diabetes.
Design: Randomized, placebo-controlled clinical trial evaluating cinnamon supplementation.
Key findings:
• Cinnamon did not significantly improve fasting glucose compared with placebo
• Lipid biomarkers did not significantly improve
• This trial contributed to the recognition that cinnamon study findings are heterogeneous
• Differences in population, baseline metabolic status, formulation, and study duration may influence observed results
5) Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. Journal of the American Board of Family Medicine. 2009.
PMID: 19734396
DOI: https://doi.org/10.3122/jabfm.2009.05.080093
Population: Adults with type 2 diabetes and HbA1c greater than 7.0%.
Design: Randomized controlled trial evaluating 1 g/day cinnamon plus usual care versus usual care alone for 90 days.
Key findings:
• HbA1c decreased by approximately 0.83% in the cinnamon group
• HbA1c decreased by approximately 0.37% in the usual-care group
• The study suggested an association between cinnamon use and HbA1c improvement under study conditions
• Results should be interpreted in context because treatment adjustments and usual care continued during the trial
6) Akilen R, Tsiami A, Devendra D, et al. Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial. Diabetic Medicine. 2010.
PMID: 20854384
DOI: https://doi.org/10.1111/j.1464-5491.2010.03079.x
Population: Adults with poorly controlled type 2 diabetes.
Design: Randomized, placebo-controlled, double-blind trial evaluating 2 g/day cinnamon for 12 weeks.
Key findings:
• HbA1c decreased in the cinnamon group under study conditions
• Systolic and diastolic blood pressure reductions were also reported
• The study is frequently cited because it evaluated both glycemic and blood pressure biomarkers
• Findings may not apply equally across populations or cinnamon preparations
7) Lu T, Sheng H, Wu J, et al. Cinnamon extract improves fasting blood glucose and glycosylated hemoglobin level in Chinese patients with type 2 diabetes. Nutrition Research. 2012.
PMID: 22749176
DOI: https://doi.org/10.1016/j.nutres.2012.05.003
Population: Adults in China with type 2 diabetes.
Design: Randomized, double-blind clinical study evaluating cinnamon extract.
Key findings:
• Fasting blood glucose improved in the cinnamon extract groups
• HbA1c improved under study conditions
• Serum lipid biomarkers and liver transaminases were not significantly changed
• The study added evidence from a population not represented in several earlier trials
8) Zare R, Nadjarzadeh A, Zarshenas MM, et al. Efficacy of cinnamon in patients with type II diabetes mellitus: a randomized controlled clinical trial. Clinical Nutrition. 2019.
PMID: 29605574
DOI: https://doi.org/10.1016/j.clnu.2018.03.003
Population: Adults with type 2 diabetes.
Design: Randomized controlled clinical trial evaluating cinnamon supplementation.
Key findings:
• Improvements were reported in selected glycemic biomarkers
• Improvements were also reported in anthropometric and lipid-related measures
• Some effects appeared more prominent in individuals with higher baseline body mass index
• The study contributed to later meta-analyses evaluating cinnamon across metabolic endpoints
9) Allen RW, Schwartzman E, Baker WL, et al. Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis. Annals of Family Medicine. 2013.
PMID: 24019277
DOI: https://doi.org/10.1370/afm.1517
Population: Adults with type 2 diabetes across randomized controlled trials.
Design: Systematic review and meta-analysis of 10 randomized controlled trials.
Key findings:
• Cinnamon was associated with reductions in fasting plasma glucose
• Reductions were also reported in total cholesterol, LDL cholesterol, and triglycerides
• HDL cholesterol increased modestly in pooled analyses
• HbA1c did not significantly improve in pooled analyses
• The authors emphasized heterogeneity across trials and lack of standardization in cinnamon preparations
10) Deyno S, Eneyew K, Seyfe S, et al. Efficacy and safety of cinnamon in type 2 diabetes mellitus and pre-diabetes patients: a meta-analysis and meta-regression. Diabetes Research and Clinical Practice. 2019.
PMID: 31425768
DOI: https://doi.org/10.1016/j.diabres.2019.107815
Population: Adults with type 2 diabetes or prediabetes across randomized controlled trials.
Design: Systematic review, meta-analysis, and meta-regression of randomized controlled trials.
Key findings:
• Cinnamon significantly reduced fasting blood glucose in pooled analyses
• HOMA-IR also decreased in pooled analyses
• HbA1c and lipid-profile changes were not consistently significant
• High heterogeneity was noted across included studies
• The authors emphasized the need for more standardized cinnamon formulations in future trials
11) Zarezadeh M, Musazadeh V, Foroumandi E, et al. The effect of cinnamon supplementation on glycemic control in patients with type 2 diabetes or with polycystic ovary syndrome: an umbrella meta-analysis on interventional meta-analyses. Diabetology & Metabolic Syndrome. 2023.
PMID: 37316893
DOI: https://doi.org/10.1186/s13098-023-01057-2
Population: Adults with type 2 diabetes or women with polycystic ovary syndrome across prior meta-analyses.
Design: Umbrella meta-analysis of interventional meta-analyses.
Key findings:
• Cinnamon supplementation was associated with reductions in fasting plasma glucose
• Pooled analyses also reported reductions in insulin, HOMA-IR, and HbA1c
• Effects appeared stronger in type 2 diabetes populations in some subgroup analyses
• The authors noted substantial variability across prior meta-analyses and study designs
• Findings support an association with glycemic biomarkers, while reinforcing the need for careful interpretation
Cardiovascular and Lipid Support
Evidence strength: Low to Moderate.
Several trials and pooled analyses have examined the relationship between cinnamon and lipid biomarkers, blood pressure, and cardiometabolic risk markers. Findings are mixed, with some analyses reporting modest favorable changes and others showing limited or inconsistent effects.
12) Maierean SM, Serban MC, Sahebkar A, et al. The effects of cinnamon supplementation on blood lipid concentrations: a systematic review and meta-analysis. Journal of Clinical Lipidology. 2017.
PMID: 28887086
DOI: https://doi.org/10.1016/j.jacl.2017.08.004
Population: Adults across randomized controlled trials evaluating lipid biomarkers.
Design: Systematic review and meta-analysis.
Key findings:
• Cinnamon supplementation was associated with reductions in triglycerides
• Total cholesterol also decreased in pooled analyses
• LDL cholesterol and HDL cholesterol effects were not consistently significant
• Findings suggested lipid-related effects may depend on baseline metabolic status, dose, formulation, and trial duration
13) Mousavi SM, Karimi E, Hajishafiee M, et al. Anti-hypertensive effects of cinnamon supplementation in adults: a systematic review and dose-response meta-analysis of randomized controlled trials. Critical Reviews in Food Science and Nutrition. 2020.
PMID: 31617744
DOI: https://doi.org/10.1080/10408398.2019.1678012
Population: Adults across randomized controlled trials evaluating blood pressure.
Design: Systematic review and dose-response meta-analysis of randomized controlled trials.
Key findings:
• Cinnamon supplementation was associated with reductions in systolic blood pressure
• Diastolic blood pressure reductions were also reported
• The magnitude of effect varied across studies
• Results suggest possible blood pressure effects under study conditions, but the evidence remains less developed than for glucose-related biomarkers
14) Jamali N, Kazemi A, Saffari-Chaleshtori J, et al. The effect of cinnamon supplementation on lipid profiles in patients with type 2 diabetes: a systematic review and meta-analysis of clinical trials. Complementary Therapies in Medicine. 2020.
PMID: 33220625
DOI: https://doi.org/10.1016/j.ctim.2020.102571
Population: Adults with type 2 diabetes across clinical trials.
Design: Systematic review and meta-analysis of clinical trials.
Key findings:
• Triglycerides decreased in pooled analyses
• Total cholesterol and LDL cholesterol also decreased in pooled analyses
• HDL cholesterol did not significantly change
• Findings suggest modest lipid-biomarker effects in selected type 2 diabetes study populations
• Heterogeneity across trials limits certainty
Other Support
Evidence strength: Low.
Other areas of cinnamon research include body composition, oxidative stress, inflammatory biomarkers, and safety. These areas are biologically plausible but generally less established than glucose-related research.
15) Mousavi SM, Rahmani J, Kord-Varkaneh H, et al. Cinnamon supplementation positively affects obesity: a systematic review and dose-response meta-analysis of randomized controlled trials. Clinical Nutrition. 2020.
PMID: 30799194
DOI: https://doi.org/10.1016/j.clnu.2019.02.017
Population: Adults across randomized controlled trials evaluating body composition.
Design: Systematic review and dose-response meta-analysis.
Key findings:
• Cinnamon supplementation was associated with modest improvements in body weight-related measures in pooled analyses
• Effects varied by dose and duration
• Findings should be interpreted cautiously because many included trials were not primarily designed as weight-loss studies
• Cinnamon should be viewed as a studied botanical within broader metabolic research, not as a stand-alone weight-management intervention
16) Gu DT, Tung TH, Jiesisibieke ZL, et al. Safety of Cinnamon: An Umbrella Review of Meta-Analyses and Systematic Reviews of Randomized Clinical Trials. Frontiers in Pharmacology. 2022.
PMID: 35115937
DOI: https://doi.org/10.3389/fphar.2021.790901
Population: Participants included in prior systematic reviews and meta-analyses of randomized clinical trials.
Design: Umbrella review evaluating safety findings across systematic reviews and meta-analyses.
Key findings:
• No significant increase in adverse events was reported across reviewed analyses
• Most reported adverse effects were mild when present
• The authors noted limitations in the quality of available reviews
• Safety interpretation should consider cinnamon species, dose, duration, coumarin exposure, product quality, and individual susceptibility
Educational Notice
These summaries are provided for educational purposes to review published scientific literature and should not be interpreted as medical advice, diagnosis, or treatment recommendations. Readers should consult qualified healthcare professionals for personal medical decisions.
FDA Disclaimer
These statements have not been evaluated by the U.S. Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease.
FTC Affiliate Disclosure
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