Efficacy of cinnamon in patients with type II diabetes mellitus: A randomized controlled clinical trial

Background & aims: Multiple studies have evaluated the hypoglycemic effect of cinnamon in patients with diabetes mellitus (DM) type II, with conflicting results. Differences in Baseline Body Mass Index (BMI) of patients may be able to explain the observed differences in the results. This study was designed to evaluate the effect of cinnamon supplementation on anthropometric, glycemic and lipid outcomes of patients with DM type II based on their baseline BMI.

Methods: The study was designed as a triple-blind placebo-controlled randomized clinical trial, using a parallel design. One hundred and forty patients referred to Diabetes Clinic of Yazd University of Medical Sciences with diagnosis of DM type II were randomly assigned in four groups: cinnamon (BMI ≥ 27, BMI < 27) and Placebo (BMI ≥ 27, BMI < 27). Patients received cinnamon bark powder or placebo in 500 mg capsules twice daily for 3 months. Anthropometric, glycemic and lipid outcomes were measured before and after the intervention.

Result: Cinnamon supplementation led to improvement of all anthropometric (BMI, body fat, and visceral fat), glycemic (FPG, 2hpp, Hb_A1C, Fasting Insulin, and Insulin Resistance), and lipids (Cholesterol Total, LDL-c and HDL-c) outcomes (except for triglycerides level). All observed changes (except for Cholesterol Total and LDL-c) were significantly more prominent in patients with higher baseline BMI (BMI ≥ 27).

Conclusion: Based on the study findings, cinnamon may improve anthropometric parameters, glycemic indices and lipid profile of patients with type II diabetes. These benefits are significantly more prominent in patients with higher baseline BMI (BMI ≥ 27). The trial protocol was registered in Iranian Registry of Clinical Trials database (registration ID: IRCT2017031133015N1).