Randomized Controlled Clinical Trial of Cinnamon to Lower Hemoglobin A1c

As the worldwide incidence of diabetes increases, the search for dietary adjuncts to treat this life-altering disease becomes far ranging. Cinnamon is purported to be a natural insulin sensitizer without any known adverse events. Both in vitro and in vivo animal studies have shown that cinnamon is an insulin sensitizer1. Several compounds within cinnamon have been identified as possible sources of this sensitization process.

To-date, three small randomized trials studying cinnamon in human diabetics have been published. Khan et al. reported that fasting serum glucose could be reduced by 18-29% after 40 days of supplementation with 1, 3, or 6 g of cinnamon (Cinnamomum cassia) in type 2 diabetics. 2 This study had several limitations that included failure to measure hemoglobin A1C, all patients were Pakistani, and no power analysis was documented. Vanschoonbeek, et al.3 report a small RCT of postmenopausal women with well-controlled type 2 diabetes which showed no change in HbA1C or fasting glucose. Once again no power analysis is reported. Mang et al. 4 conducted a RCT of type 2 diabetics treated with aqueous extract of cinnamon for 4 months. They report a 15% decrease in fasting glucose and no change in HbA1C over the duration of this trial. Subjects had HbA1C less than 7% and again no power analysis was included in this study.

This study will address whether cinnamon at the dose of 1g daily in addition to usual care lowers hemoglobin A1c compared to usual care. Power analysis indicates that 63 per group are needed and we will recruit 70 patients.