Efficacy of Cinnamon as an Adjuvant in Reducing the Glycemic Biomarkers of Type 2 Diabetes Mellitus: A Three-Month, Randomized, Triple-Blind, Placebo-Controlled Clinical Trial

Abstract

The major aim of this randomized, placebo-controlled, triple-blind clinical trial was to evaluate the efficacy of cinnamon as an adjuvant treatment in reducing glycemic levels in people with type 2 diabetes, compared to a placebo. The study was conducted between August and December 2019, with 160 people with type 2 diabetes, in five Primary Health Units, in Parnaíba, Brazil. Inclusion criteria were: persons of both genders using oral antidiabetic agents, with glycated hemoglobin ≥ 6.0%, and between 18 and 80 years of age. The primary outcome was change in glycated hemoglobin levels after 90 days of intervention. Other biomarkers evaluated were fasting blood glucose, insulin level, and HOMA-IR index. Participants were divided equally into two groups of 80 individuals each, and were given 3 g capsules of either cinnamon or placebo to be taken in combination with their usual oral antidiabetic agents. After 90 days, participants in the cinnamon group had statistically significant reductions of 0.2% of glycated hemoglobin and 0.55 mmol/L of fasting venous glucose, when compared with the placebo group. Cinnamon reduced the glycemic measures of persons with type 2 diabetes, albeit with modest reductions. TRIAL: RBR-2KKB6D.

Keywords:

• Cinnamon
• clinical trial
• glucose
• placebo
• type 2 diabetes mellitus

Acknowledgments

The Higher Education Improvement Coordination (CAPES) and the National Council for Scientific and Technological Development (CNPq) provided funding for this study. The Federal University of Ceará and National Council for Scientific and Technological Development (CNPq) provided support to the primary author.

Authors contribution

JCGLN contributed to conception, study design, execution, data acquisition, interpretation of results, and manuscript writing. MMCD contributed to conception, study design, execution, interpretation of results, manuscript writing, and financed the intervention delivery. MAC contributed to statistical analysis, interpretation of results, and manuscript writing. RWJFF, MFMA, CRST, GCNC, KWSCL, RLLM, AMPGA, and MLZ contributed to manuscript writing. All authors critically reviewed and revised the manuscript and have read and approved the final version. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

Disclosurs statement

The authors have no conflict of interest.

Additional information

Funding

National Council for Scientific and Technological Development – CNPq. The sponsor of this study was not involved in the study design, data collection, analysis, and interpretation, writing of the report, and did not impose restrictions on the publication of the report. The sponsor provided collecting data assistance only.